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Title:
ANTI-MYOPIA TRAINING EYEGLASSES
Document Type and Number:
WIPO Patent Application WO/2016/150777
Kind Code:
A1
Abstract:
The present invention provides anti-myopia smart eyeglasses and a method operated at the smart eyeglasses. The smart eyeglasses comprises: a visualizing unit configured for projecting at least one image at a focus spot for the view of a wearer of the eyeglasses; a processing unit configured for controlling the eyeglasses to work in a natural mode and a training mode, wherein the processing unit is further configured for: controlling the eyeglasses to allow the wearer of the eyeglasses to focus at an object that the wearer is looking at in the natural mode; and controlling the visualizing unit to project at least one image on at least one different focus point for attracting the view of the wearer of the eyeglasses to focus nearby or farther away in the training mode. By using the smart eyeglasses, the wearer may have the anti-myopia eye exercise while doing indoor routine activities, bringing great convenience and encouraging people to have eye exercises regularly while bringing a similar treatment effect as playing outdoors.

Inventors:
AARTS RONALDUS MARIA (NL)
AARTS VINCENT ALEXANDER RUDOLF (NL)
Application Number:
PCT/EP2016/055613
Publication Date:
September 29, 2016
Filing Date:
March 16, 2016
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
KONINKLIJKE PHILIPS NV (NL)
International Classes:
G02B27/01; G02C7/00
Domestic Patent References:
WO2014174067A12014-10-30
WO2014174067A12014-10-30
Foreign References:
DE10217347A12003-11-06
US20110205484A12011-08-25
DE10217344A12003-11-06
US20140036374A12014-02-06
US20040165099A12004-08-26
US7298414B22007-11-20
Other References:
KATHRYN A ET AL.: "Outdoor Activity Reduces the Prevalence of Myopia in Children", OPHTHALMOLOGY, vol. 115, 2008, pages 1279 - 1285
Attorney, Agent or Firm:
NIESSEN, Arnoldus Jeroen et al. (NL)
Download PDF:
Claims:
CLAIMS:

1. Smart eyeglasses (200) for eyesight training, comprising:

a visualizing unit (202) configured for projecting at least one image at a focus spot for the view of a wearer of the eyeglasses (200);

a processing unit (201) configured for controlling the eyeglasses (200) to allow the wearer of the eyeglasses (200) to focus on an object that the wearer is looking at in a natural mode,

characterized in that, the processing unit (201) is further configured forcontrolling the visualizing unit (202) to project at least one image on at least one different focus point , so as to attract the view of the wearer of the eyeglasses (200) away from the object and focus nearby or farther away onto the projected image in a training mode.

2. The eyeglasses (200) of claim 1, wherein the processing unit (201) is configured for detecting a first time period for which the wearer of the eyeglasses (200) has been looking at the object in the natural mode, and switching the eyeglasses (200) from the natural mode to the training mode when the detected first time period exceeds a first threshold.

3. The eyeglasses (200) of claim 2, wherein the processing unit (201) is configured for detecting a second time period for which the wearer of the eyeglasses (200) has been looking at said at least one image projected by the visualizing unit (202) in the training mode, and switching from the training mode back to the natural mode when the detected second time period exceeds a second threshold.

4. The eyeglasses (200) of claim 3, wherein the processing unit (201) is configured for controlling the visualizing unit (202) to project images at different focus distances alternatively in the training mode.

5. The eyeglasses (200) of any of claims 1-4, further comprising at least one outward-facing camera and/or at least one inward-facing camera, wherein

said at least one outward-facing camera is configured for capturing images in front of the wearer's eyesight,

said at least one inward-facing camera is configured for capturing images of the wearer's eyes,

said processing unit is configured for tracking a focus distance of the wearer's eyes based on the images captured by the at least one outward-facing camera and/or the at least one inward- facing camera, and

said processing unit (201) is configured for determining to switch the eyeglasses

(200) from the natural mode to the training mode when the tracking indicates the wearer's eyes focus close by for a time period of the first threshold in the natural mode and/or to switch the eyeglasses (200) from the training mode to the natural mode when the tracking indicates the wearer's eyes focus far away for a time period of the second threshold in the training mode.

6. The eyeglasses (200) of any of claims 1-5, further comprising:

a communication unit (204) configured for interfacing with an external device; wherein the processing unit (201) is configured for receiving control information of the external device via the communication unit (204), wherein the control information is generated when the external device is operated, and the processing unit

(201) is configured for identifying whether the wearer's eyes focus close by based on the control information.

7. The eyeglasses (200) of any of claims 1-5, wherein the at least one image displayed in the training mode is at least one exercising picture or video for eye muscle exercises or is at least one image or video being viewed in the first mode.

8. The eyeglasses (200) of any of claims 1-5, wherein the processing unit (201) is configured to control the visualizing unit (202) to display a message for prompting eye exercises or to control an audio transducer of the eyeglasses (200) to vocally output a message for prompting eye exercises in the training mode.

9. The eyeglasses (200) of any of claims 1-5, further comprising a user interface, wherein the processing unit (201) is configured for receiving via the user interface at least one of the following user inputs: a value of the first threshold, a value of the second threshold, an instruction for switching from the natural mode to the training mode, an instruction for switching from the training mode to the natural mode, an instruction for postpone the switching from the natural mode to the training mode, an instruction for postpone the switching from the training mode to the natural mode.

10. A computer program product comprising a computer-readable medium embodying computer program code for, when executed on at least a processing unit (201) and/or a visualizing unit (202) of smart eyeglasses (200) for eyesight training according to any of claims 1-9, implementing the step of:

allowing the view of the wearer of the eyeglasses (200) to focus on an object that the wearer is looking at in a natural mode;

characterized in that the computer program code further implements the step of projecting at least one image on at least one focus point so as to attract the view of the wearer of eyeglasses (200) from the object and focus nearby or farther away onto the projected image in a training mode.

11. The computer program product of claim 10, wherein the computer program code implements the step of:

detecting a first time period for which the wearer of the eyeglasses (200) has been looking at the object in the natural mode, and

switching the eyeglasses (200) from the nature mode to the training mode when the detected first time period exceeds a first threshold.

12. The computer program product of claim 11, wherein the computer program code implements the step of:

detecting a second time period for which the wearer of the eyeglasses (200) has been looking at said at least one image projected by the visualizing unit (202) in the training mode, and

switching the eyeglasses (200) from the training mode back to the natural mode when the detected second time period exceeds a second.

13. The computer program product of claim 12, wherein the computer program code implements the step of:

controlling the visualizing unit (202) to project images at different focus distances alternatively in the training mode.

14. The computer program product of any of claims 10-13, wherein the computer program code implements the step of:

capturing images in front of the wearer's eyesight and/or images of the user's eyes;

tracking a focus distance of the wearer's eyes based on the captured images; and switching from the natural mode to the training mode when the tracking indicates the wearer's eyes focus for a time period of the first threshold in the natural mode and/or switching from the training mode to the natural mode when the tracking indicates the wearer's eyes focus far away for a time period of the second threshold in the training mode.

15. The computer program product of any of claims 10 to 14, wherein the computer program code implements the step of:

receiving control information of an external device, wherein the control information is generated when the external device is operated, and identifying whether the wearer's eyes focus close by based on the control information.

Description:
ANTI-MYOPIA TRAINING EYEGLASSES

FIELD OF THE INVENTION

The invention relates to smart eyeglasses, and, in particular, it relates to anti-myopia training eyeglasses.

BACKGROUND OF THE INVENTION

Myopia is inability to see things properly when they are far away. Such an eye condition not only brings inconvenience for people's life but also poses significant costs for optical correction and potential treatment for associated cataract and glaucoma in the longer term.

The prevalence of myopia has increased dramatically, especially in some highly educated groups. In parallel with the increase in overall myopia, there has been a rise in the prevalence of high myopia. Furthermore, myopia is appearing with greater prevalence in young children, which places these children at greater risk of developing high myopia, with its associated complications.

A research on factors that could increase the risk of myopia (Kathryn A, et al, "Outdoor Activity Reduces the Prevalence of Myopia in Children", Ophthalmology, 115: 1279-1285, 2008) shows that outdoor activity could reduce the possibility of getting myopia.

The document DE10217344A1 proposes an eye treatment device, which dynamically displays an object or figure on a screen in such a way that it is sometimes blurred and sometimes sharp, bringing the object virtually close to a patient and then far away, in a rhythmic manner.

However every time the patient takes eye treatment with this device, the patient needs to spend quite a long time dedicated for eye treatment. Such inconvenience discourages people to use the device even for the benefit of their eyes.

WO2014/174067A1 proposes a method of using a head mounted electro-optical device according to visual parameters of a wearer. Such a head mounted device can be used as a pair of multifocal eye glasses which has a first visual zone for far vision and a second zone for near vision, and can be adapted according to the visual parameters of the wearer. When the wearer is misusing the head mounted device, e.g. when a myopic wearer is glazing at a near object through the first visual zone for far vision, a visual signal is given to reminder the wearer to glaze through the correct visual zone. By this means it may help slow myopic progress.

The present invention intends to suggest a new approach to train the eyesight of the wearer of smart glasses, so as to mitigate visual fatigue and prevent from worth myopia.

SUMMARY OF THE INVENTION

In view of the situation of prevalence of myopia, the present invention aims to provide a device which facilitates preventing myopia or at least alleviating the development of myopia without disturbing the user's routine activity or bringing much burden for the user, especially without expending much time specifically for the eye treatment.

According to one aspect of the present invention, it provides smart eyeglasses for eyesight training, comprising: a visualizing unit configured for projecting at least one image at a focus spot for the view of a wearer of the eyeglasses; a processing unit configured for controlling the eyeglasses to allow the wearer of the eyeglasses to focus on an object that the wearer is looking at in a natural mode. The processing unit is further configured for controlling the visualizing unit to project at least one image on at least one different focus point , so as to attract the view of the wearer of the eyeglasses away from the object and focus nearby or farther away onto the projected image in a training mode.

Bifocal head-up display systems have been developed, e.g. mentioned in US2014/0036374A1, in which a projector is used to project images onto two image planes of different distances from a vehicle operator. The similar projection principle can be used for the smart eyeglasses of the invention.

In the natural mode, the eyeglasses do not project a distracting image to distract the wearer so that the wearer can act as usual, such as reading, writing, watching screen and so on. In the training mode, the eyeglasses can operate to project at least one image, e.g., still pictures or video, to distract the wearer's eyes to focus nearby or farther away than in the natural mode. For example, when a wearer is reading a book or viewing a screen, an image is projected at a farther focus point in the wearer's vision range in the training mode. The distracting image is easy to be noticed by the wearer and may guide the wearer's eyes to focus farther away. In this way, the focus point of the wearer's eyes has to change over time under the direction of the eyeglasses, so that the eye activity as playing outdoors is simulated during the wearer's usual indoor activity, without requiring the wearer to spend specific time only for eye treatment.

According to an embodiment of the present invention, the visualizing unit can be controlled to project images on different focus points, e.g. on a close by focus point and a focus point farther away. In this embodiment, by controlling the visualizing unit to project images at different focus points, the eyeglasses are not only an eye exercising device but also a display which may replace the typical screen of a device such as smart phone, e-reader, PC and so on.

According to an embodiment of the present invention, the processing unit is configured for detecting a first time period for which the wearer of the eyeglasses has been looking at the object in the natural mode, and switching the eyeglasses from the natural mode to the training mode when the detected first time period exceeds a first threshold. In another embodiment, the processing unit is configured for detecting a second time period for which the wearer of the eyeglasses has been looking at said at least one image projected by the visualizing unit in the training mode, and switching from the training mode back to the natural mode when the detected second time period exceeds a second threshold. In such a way, the eyeglasses may direct the user to perform the eye exercises periodically.

According to an embodiment of the present invention, the eyeglasses may comprise at least one outward-facing camera and/or at least one inward-facing camera. The at least one outward- facing camera is configured for capturing images in front of the wearer's eyesight, and the at least one inward- facing camera is configured for capturing images of the wearer's eyes. The processing unit is configured for tracking a focus distance of the wearer's eyes based on the images captured by the at least one outward-facing camera and/or the at least one inward-facing camera, and the processing unit is configured for determining to switch the eyeglasses from the natural mode to the training mode when the tracking indicates the wearer's eyes focus close by for a time period of the first threshold in the natural mode and/or switch the eyeglasses from the training mode back to the natural mode when the tracking indicates the wearer's eyes focus far away for a time period of the second threshold in the training mode. In this embodiment, through tracking the focus distance of the wearer's eyes, the switching of the two modes may be controlled more precisely. For example, light retroreflected from eyes of the wearer can be captured by an inward- facing camera integrated in the eyeglasses when the wearer's eyesight is looking at an object, so as to create a retroreflected image, which can be focused onto an image sensor, and the focus distance of the eyes of the wearer can be determined by means of processing the focused image.

According to an embodiment of the present invention, the eyeglasses may comprise a communication unit configured to interface with an external device. The processing unit is configured for receiving control information of the external device via the communication unit, wherein the control information is generated when the external device is operated. The processing unit is configured for identifying whether the wearer's eyes focus close by based on the received control information of the external device This is based on the estimation that the received control information of the external device may indicate the external device is being operated by the wearer i.e., the wearer is looking at the screen of the external device.

According to an embodiment of the present invention, the processing unit is configured for controlling the visualizing unit to project the image at a position where there is no object to focus close by in the training mode. For example, the position may be a window, and when the wearer's eyes are attracted to such a position, they will focus far away on the landscape.

According to an embodiment of the present invention, the at least one image displayed in the training mode is at least one exercising picture or video used for eye muscle exercises or is at least one image or video being viewed in the natural mode. By using the same source which is being viewed in the natural mode as the image to be projected in the training mode, the wearer may be allowed to have the eye exercising without breaking his current activity.

According to an embodiment of the present invention, the processing unit is configured to control the visualizing unit to display a message for prompting eye exercises or control an audio transducer of the eyeglasses to vocally output a message prompting for eye exercises in the training mode. In this way, the message provides an auxiliary approach to prompt the wearer to perform eye exercises.

According to an embodiment of the present invention, the eyeglasses may comprise a user interface. The processing unit may receive via the user interface at least one of the following user inputs: a value of the natural time period, a value of the training time period, an instruction for switching from the natural mode to the training mode, an instruction for switching from the natural mode to the natural mode, an instruction for postpone the switching from the natural mode to the training mode, and an instruction for postpone the switching from the training mode to the natural mode. In this way, the user interface allows the user to operate the eyeglasses flexibly.

According to one aspect of the present invention, it provides a computer program product comprising a computer-readable medium embodying computer program code for, when executed on at least a processing unit and/or a visualizing unit of aforementioned smart eyeglasses for eyesight training, implementing the step of allowing the view of the wearer of the eyeglasses to focus on an object that the wearer is looking at in the natural mode. The computer program code further implements the step of projecting at least one image on at least one focus point, so as to attract the view of the wearer of the eyeglasses away from the object and focus nearby or farther away onto the projected image in a training mode.

Other objects and advantages of the present invention will become more apparent and will be easily understood with reference to the description made in combination with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

The present invention will be described and explained hereinafter in more detail in combination with embodiments and with reference to the drawings, wherein:

Fig. 1 is a diagram illustrating an exemplary appearance of smart eyeglasses in accordance with an embodiment of the present invention;

Fig. 2 is a block diagram illustrating the structure of smart eyeglasses in accordance with an embodiment of the present invention; and

Fig. 3 is a block diagram illustrating a process for adjusting eye focus distance operated at smart eyeglasses in accordance with an embodiment of the present invention, which process can be implemented by a computer program product.

The same reference signs in the figures indicate similar or corresponding feature and/or functionality.

DETAILED DESCRIPTION

The embodiment of the present invention will be described hereinafter in more detail with reference to the drawings.

Fig. 1 shows an exemplary appearance of smart eyeglasses 100. An example of smart eyeglasses may be a Google Glass device (http://en.wikipedia.org/wiki/Google_Glass), which typically includes an eyeglasses frame and components mounted on the frame such as a processor, a camera, a projector and so on.

The present invention may be implemented in a Google Glass device, but it should be noted that the smart eyeglasses do not need to include all the components typically equipped on a Google Glass device. Although it is called smart eyeglasses, other appearances are possible, for example, the present invention may be implemented in the shape of helmet, which should also fall within the scope of the present invention if it implements the similar functions as the present invention.

Fig. 2 shows an exemplary block diagram illustrating the structure of the smart eyeglasses 200 according to embodiments of the present invention.

As shown in Fig. 2, the smart eyeglasses comprise a processing unit 201, a visualizing unit 202, a sensing unit 203, a communication unit 204 and a user interface unit 205. It should be noted that in different embodiments, the implementation of the smart eyeglasses may not include all the components as shown in Fig. 2, or may need more components.

In an embodiment, the smart eyeglasses 200 include the processing unit 201 and the visualizing unit 202. The processing unit 201 may be a processor, such as a central processing unit (CPU), which controls the operation of the smart eyeglasses. The visualizing unit 202 may include a projector and may optionally include a set of lens. The visualizing unit 202 may allow the view of the wearer of the eyeglasses to focus on an object that the wearer is looking at, and project images at different focus spots for the wearer's view under the control of the processing unit 201.

The processing unit 201 may be configured to control the eyeglasses to work in a natural mode and a training mode. In the natural mode, eyes of the user wearing the eyeglasses are allowed to loot at the object in a natural way. And in the training mode, the visualizing unit 202 may be controlled by the processing unit 201 to project at least one image which attracts the user's eyes to focus nearby or farther away.

In other words, in the natural mode, the smart eyeglasses 200 do not project an image or a distracting image to distract the user, allowing the user to acts as usual, such as reading, writing, watching screen and so on, without the disturbance of the distracting image. Alternatively, in the natural mode, the visualizing unit 202 may be controlled by the processing unit 201 to project an image of the object onto a focus point, so that the eyes of the wearer can see the object clearly in a natural way, just like the wearer is wearing his/her optical eyeglasses. Then in the training mode, the visualizing unit 201 is controlled by the processing unit 202 to project at least one image on at least one focus point nearby or farther away, so that the wearer has to excise his/her eyeball muscles to adjust the focus distance.

For example, a focus distance less than 16 inches or 41 centimeters can be considered as a natural focus point. It should be noted that, the value of a normal reading distance is not fixed, for example 50 centimeters may also be regarded as a normal reading distance. The present invention is not limited to the specific focus distance. In the context of the present invention, the natural mode may refer to a status that a person is doing a certain activity with his eyes, for example, reading a book, looking at a screen of a cell phone, a PC or a television. In the natural mode, the smart eyeglasses 200 do not affect the person's routine activity, and only in the training mode, the smart eyeglasses 200 project images on at least one different focus point, i.e., nearby or further away, than in the natural mode, attracting the user to change his eye focus. In this way, the outdoor eye activity may be simulated with the aid of the smart glasses.

In an embodiment, the switching between the two modes may be based on time. For example, the processing unit 201 may be configured to determine to switch the eyeglasses from the natural mode to the training mode when a time period of a first threshold elapses in the natural mode, and determine to switch from the training mode to the natural mode when a time period of a second threshold elapses in the training mode.

The processing unit 201 may set a single timer for counting the time periods, and may set two timers for counting the time periods respectively. The first and second thresholds may be preset and fixed, or may be dynamically set from time to time. For example, there may be multiple options for the time period of the first threshold, e.g., 30, 40, 50 minutes, and there may be multiple options for the time period of the second threshold, e.g. 5, 7, 9 minutes. Each time the processing unit 201 determines to switch the mode, the processing unit 201 may randomly select one of the multiple optional time periods of the threshold for such mode. In this way, the switching of the modes may become more irregular, resulting in a better simulation to the outdoor eye activity.

The first and second thresholds may be default values, or may be set or modified by the wearer via the user interface 205. The user interface allows the wearer to operate on the smart eyeglasses. The wearer may manually input instruction via the user interface 205 to switch the eyeglass from the natural mode to the training mode or from the training mode to the natural mode. For example, the switching of the modes may occur at an improper time, and the wearer may manually input instruction via the user interface 205 to postpone the switching of the eyeglass from one of the natural and training modes to the other.

In an embodiment, the processing unit 201 may tracking the focus distance with the aid of the sensing unit 203. The sensing unit 203 may include at least one outward- facing camera and/or at least one inward-facing camera. The at least one outward-facing camera may be configured to capture images in front of the wearer's eyesight, and the at least one inward-facing camera may be configured to capture images of the wearer's eyes. The processing unit 201 is configured to track the focus distance of the wearer's eyes based on the images captured by the at least one outward-facing camera and/or the at least one inward- facing camera. The processing unit 201 may be configured to determine to switch the eyeglasses from the natural mode to the training mode when the tracking indicates that the time period for which the wearer has been looking at the object in the natural mode exceeds the first threshold in the natural mode, and/or to switch the eyeglasses from the training mode to the natural mode when the tracking indicates that the time period for which the wearer has been looking at the at least one image projected by the visualizing unit exceeds the second threshold in the training mode.

Various existed eye tracking techniques may be used to track the focus distance of the wearer's eyes. For example, US2004165099 describes an exemplary method for determine the focus distance of wearer's eyes.

In an embodiment, the sensing unit 203 may include only one outward-facing camera which is configured to capture pictures in front of the wearer's eyes. Focus distance of the wearer's eyes may be estimated based on the single outward- facing camera. In another embodiment, the sensing unit may include multiple outward-facing cameras, for example two outward-facing cameras, which may make stereoscopic viewing possible for better depth estimation, and thus help obtaining more accurate focus distance estimation. In another embodiment, the sensing unit 203 may include one inward- facing camera which is configured to capture images of wearer's eye. Focus distance of the wearer's eyes may be estimated based on the single inward-facing camera. In another embodiment, the sensing unit 203 may include multiple inward-facing cameras, for example, two inward-facing cameras with each camera being used for an eye of the wearer.

In an embodiment, considering the typical application circumstances of the present invention, the smart glasses may determine whether the wearer's eyes are in a focus close by status based on the characteristics of the objects being looked at by the wearer. For example, people may look at a screen of a device such as a computer, a television, a tablet, a smart phone, and/or an e-reader. The screen of the device may typically have some special characteristics such as a specific refresh rate, a certain amount of light output, and a regular shape such as rectangle. The processing unit 201 may identify at least one of the characteristics based on the pictures captured by the outward- facing camera.

The processing unit 201 may detect the focus distance based on the size of the screen shown in the image captured by the outward-facing camera. For example, if the processing unit 201 detects that a certain percentage portion of the captured image is covered by bright light and the portion is in a regular shape such as rectangle, the processing unit 201 may identify that the wearer is looking at a screen closely, i.e. the eyeglasses is in the nature mode. As an unlimited example, the certain percentage portion may be 40%.

The processing unit 201 may also detect the focus distance when the wearer is reading a physical book or a document having a regular shape. Similarly, the processing unit 201 may detect the shape of the physical book, and may determine whether the wearer is looking at it, i.e. the eyeglasses is in the nature mode, based on the shape and/or the size of the book in the captured image.

In an embodiment, the processing unit 201 may estimate the focus distance of the wearer's eye even without the aid of the sensing unit 203.

The communication unit 204 may be configured to interface with an external device, such as the above mentioned PC, tablet, smart phone, and e-reader. The processing unit 201 may be configured to receive control information of the external device via the communication unit 204. The control information is generated when the external device is operated by the wearer. For example, the control information may correspond to the instructions generated when buttons, mouse, keyboard, and/or touch screen of the external device are operated. Generally, the wearer is looking at the screen of the external device when he/she operates the external device. Therefore, the processing unit 201 may identify that the wearer's eyes focus close by based on the received control information.

Based on the tracking of the focus distance of the wearer's eyes, the processing unit 201 may switch the smart eyeglasses in a more precise way.

In an embodiment, the processing unit 201 may be configured to track the focus distance by using any of the above mentioned tracking method once every a predetermined time duration, count for the continuous detections of near focus distances in the natural mode, and switch from the natural mode to the training mode when the counting exceeds a first threshold number. On the other hand, the processing unit 201 may also track the focus distance of the wearer's eyes in the training mode in order to check whether the user comply with the eye exercising. Particularly, the processing unit 201 may be configured to track the focus distance once every a predetermined time duration, count for the continuous detections of far focus distances in the training mode, and switch from the training mode to the natural mode when the counting exceeds a second threshold number.

In another embodiment, the processing unit 201 may be configured to track the focus distance by using a sliding window on the captured pictures, in other words, the processing unit 201 may track the focus distance using the captured pictures covered by the sliding window, and move the sliding window to select another set of pictures to be used for the next tracking. The processing unit 201 may time the period for the continuous detections of near focus distances in the natural mode and/or far focus distances in the training mode, and switch from the training mode to the natural mode when the timing exceeds a first threshold time period and/or from the training mode to the natural mode when the timing exceeds a second threshold time period.

How to determine user's focus distance by means of photo sensors is already know in the art, e.g. disclosed by US7,298,414.

As stated above, the smart eyeglasses do not project the distracting image in the natural mode, allowing the wearer's eyes to act as usual without distraction. In the training mode, the visualizing unit 202 is configured to project the eye exercising picture or video further away than in the natural mode. By using the special eye exercising picture or video, a good effect for eye exercising may be achieved. For example, by increasing separation between associated moving images having a plurality of objects along a horizontal axis, while the wearer is trying to perceive a merged image from the associated images, the wearer's eyes will be exercised in such a manner that eye fatigue and eye strain may be relieved. Or, otherwise, eye muscles of the wearer can be stimulated by moving the eyes to tract an image that is projected and removed alternatively at random locations of the eyeglasses.

In an embodiment, the processing unit 201 may be configured to control the visualizing unit 202 to project the image at a blank position where there is no object to focus close by in the training mode. For example, the visualizing unit 202 may be directed to project the image at a window in the training mode, and when the wearer looks at the projected image, his/her eyes may be guided to the landscape through the window. In this way a good eye exercising effect may be achieved.

In an embodiment, the processing unit 201 may control the visualizing unit 202 to project the same content in the training mode as that being viewed in the natural mode. In this way, the eye exercising may be performed along with the continuation of the wearer's current activity.

As an example, the processing unit 201 may be configured to receive data, which is being displayed on the screen of the external device, via the communication unit 204 from the external device, and control the visualizing unit 202 to project the received data at a different focus farther away from the screen in the training mode.

As another example, the outward-facing camera may be configured to capture pictures for an object, for example a physical book, being viewed by the wearer's eyes. The processing unit 201 may be configured to control the visualizing unit 202 to project the captured pictures at a different focus, e.g. farther away from the object, in the training mode. The processing unit 201 may also process the captured pictures before projecting, for example, the processing unit 201 may recognize the area of interest and adjust the size of the area, and then control the visualizing unit 202 to project the area of interest at a different focus farther away from the object in the training mode. As another example, the smart eyeglasses may be used as a display. Particularly, the processing unit 201 may be configured to control the visualizing unit 202 to project images for the wearer's view at a first focus point in the natural mode. And the processing unit 201 may be configured to control the visualizing unit to project images at a training focus point farther away from the first focus point in the training mode. In this way, the user needs to change his eye focus when viewing the images projected in two modes alternatively.

In an embodiment, a prompt message may be output in the training mode to prompt the wearer to comply with the eye exercising. For example, the processing unit 201 may be configured to generate a prompt message and control the visualizing unit 202 to display the prompt message for eye exercises. As another example, the smart eyeglasses may include an audio transducer which is not shown in Fig. 2. The processing unit 201 may control the audio transducer to vocally output a prompt message prompting the wearer to follow the eye exercises in the second mode.

Fig. 3 is a block diagram illustrating a method for adjusting eye focus distance operated at smart eyeglasses. As shown in blocks 301 and 302, the eyeglasses are configured to work in a natural mode and a training mode. In block 301, the eyeglasses enter the natural mode. In the natural mode, the smart eyeglasses do not project a distracting image out of a normal reading distance, thus allowing eyes of the wearer of the eyeglasses to focus as normal without distraction. Particularly, in the natural mode, the eyeglasses may project images at a focus point close by or may not project any image, allowing the eyes of the wearer to focus in a natural way without distraction. In block 302, eyeglasses are switched to the training mode. In the training mode, the eyeglasses may project images at a focus point nearby or farther away, attracting the user's eyes to focus at a different focus distance.

As described above in conjunction with Fig. 2, the switching between the two modes may be based on a timer, and may be additionally based on the tracking of the eyes' focus distance.

The smart eyeglasses may switch from the natural mode to the training mode when a time period exceeds a first threshold in the natural mode, and may switch from the training mode to the natural mode when a time period exceeds a threshold in the training mode.

The smart eyeglasses may capture images in front of the wearer's eyesight and/or images of the wearer's eyes; track the focus distance of the wearer's eyes based on the captured images; and switch from the natural mode to the training mode when the tracking indicates the wearer's eyes focus close by for a time period of the first threshold in the natural mode and/or switch from the training mode to the natural mode when the tracking indicates the wearer's eyes focus far away for a time period of the second threshold in the training mode.

The smart eyeglasses may receive control information of an external device, wherein the control information is generated when the external device is operated, and identify that the wearer's eyes focus close by based on the control information.

The smart eyeglasses may project images at a first focus point, i.e., a normal reading distance, in the natural mode, and project images from the same source or at least one exercising image at a second focus point far away from the first focus point in the training mode.

The operations of the smart eyeglasses have been described in detail in conjunction with

Fig. 2. The method as shown in Fig. 3 may include any of the operations, which would not be repetitively described in conjunction with method as shown in Fig. 3 for sake of simplicity.

In an embodiment, the method as described above may be implemented by executing program instructions on a processor, such as the processing unit 201. Therefore the present invention may be implemented as a computer program product, which contains instructions for executing the method as described above.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention and that those skilled in the art would be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, the word "comprising" does not exclude the presence of elements or steps not listed in a claim or in the description.

The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. In the system claims enumerating several units, several of these units can be embodied by one and the same item of software and/or hardware. The usage of the words first, second and et cetera does not indicate any ordering. These words are to be interpreted as names.