OF THIS METHOD

TECHNICAL FIELD

The present invention concerns a method for manufacturing an intraocular ophthalmic lens intended for a patient. It further concerns an ophthalmic lens obtained by this method.

The intraocular ophthalmic lens can be any intraocular lens implanted in a patient's eye such as pseudo-phakic intraocular lens (lOL) or a phakic lOL for anterior or posterior chambers.

BACKGROUND ART

In the current state of the art, when the vision of a patient requires an optical correction due to a vision disorder, especially when this correction is made by an intraocular lens, the optical characteristics of the eye of the patient are measured. In particular, the type of correction is determined as well as the extent of the correction. When the type and extent of the correction have been determined, the lens whose optical characteristics are most adapted to the requirements of the patient is chosen among a range of available intraocular lenses. This lens is then generally implanted in the patient's eye, for example to replace the crystalline lens of the eye in the case of cataract surgery. In general , the available lenses exist in a predefined range of powers, for example every 0.5 diopter, to fit with the patient eye biometry, and often to correct myopia, hyperopia and astigmatism.

A problem with this kind of lens is that it only takes into account the optical characteristics of the patient's eye. Each patient with the same optical characteristics will receive the same lens. In practice, this is not satisfactory because the needs and expectations of different patients may vary. In particular, depend ing on the main activities of each patient, the lenses implanted onto the patient should be adapted.

One type of lens that takes into account the optical characteristics of the patient's eye is d isclosed in the I nternational patent appl ication WO 201 2/074742. Th is docu m ent d escribes i n particu l ar a m ethod for manufacturing a multifocal lens. The object of this method is to minimize the bother generated by the halos that are generated by a multifocal lens.

Accord ing to th is method , the shape and extension of the halos are determined by measuring the shape of the patient's cornea. The parameters of the multifocal lens are determined in order to minimize the halos when the lens is implanted in the patient's eye.

This method only applies to multifocal lenses and neither to monofocal lenses nor to lenses with an extended depth of focus. Moreover, this method does not enable real izing a lens adapted to the patient's expectations or requirements, but a lens profiled for minimizing the halos. This means that all the patients having the same optical characteristics and in particular the same shape of the cornea will receive the same lens.

DISCLOSURE OF THE INVENTION An object of the invention is to overcome the drawbacks of the intraocular lenses of the prior art by providing a lens that is tailor-made or made on demand for each patient. This means that the lens is manufactured by taking into account the patient's expectations in terms of light intensity distribution and corrections of aberrations. This also means that patients having the same optical characteristics of their eyes may have different lenses and more generally that two different patients will probably have two different lenses.

An object of the invention is obtained by a method for manufacturing an intraocular ophthalmic lens intended for a patient, this method comprising the following steps: • measuring biometric data specific to the patient;

• choosing a distribution of light to be obtained after correcting the patient's vision;

• choosing a type of aberration to be corrected and an extent of aberration correction to be applied;

• determining intrinsic parameters of the lens;

• from the results of the biometric data measurements, form the type and extent of aberrations to be corrected, from the selected light distribution and from th e determ i ned para meters of the l ens , cal cu l ati ng geometrical parameters for the lens in such a way that the set formed by the ophthalmic lens and the eye of the patient generates a light distribution specification corresponding to the chosen light distribution and to the chosen aberration corrections.

Another object of the invention is also obtained by an ophthalmic lens comprising a base correcting optical element and at least one phase distribution element wherein geometrical parameters of said lens depend on :

• biometric data specific to the patient;

• a desired d istribution of l ig ht to be obta ined after correcting the patient's vision, said lens comprising an extended depth of focus between a minimal and a maximal value of power within which light intensity is received;

• a type of aberration to be corrected and an extent of the correction of these aberrations;

• intrinsic parameters of the lens.

According to this invention, a correction of the vision to be made for a specific patient is first measured in a conventional way, to determine the type and extent of the correction which is necessary to correct the patient's vision problems. The type of correction can be for example myopia, hyperopia or more generally ametropia. The extent of the correction determines the power of the lens. The patient can then define his/her needs in terms of near vision, intermediate vision and distant vision . Th is information is then used , in combination with biometric information specific to th is patient, and is transformed to define geometrical parameters of a lens specific to this patient and corresponding to the patient's expectations. A specific lens can then be manufactured based on these geometrical parameters. Unlike the lenses of the prior art, in which only the power is selected, the lens of the present invention can offer the patient a vision that really corresponds to his/her needs and expectations.

The present invention is also advantageous in that it can be carried out on a lens having an extended depth of focus while allowing for the distribution of the light in an individual way for each patient.

Unlike multifocal lOLs which working principle is based on the splitting of light into two or more distinct foci, a lens having an extended depth of focus provides a continuous vision for a defined extended depth of focus (EDOF). The EDOF function allows to customize the focusing range along a defined distance on the optical axis.

Existing multifocal lOLs are based on the principle of creating multiple (often two or three) focal points. These kinds of lenses can lead to adverse effects such as halos, glares or ghost images (dysphotopsia). These side effects are intrinsic to their working principle that creates distinct foci who can yield to disturbance of an image on another or due to diffraction phenomenon (for diffractive multifocal lOLs).

Compared with existing multifocal lOLs, the EDOF lenses allow extending the zone along which images are formed for a progressive vision. The EDOF lenses used in the present invention use a phase distribution element that generates a light distribution along a chosen distance with an adequate intensity and resolution. This EDOF feature can be realized using a pseudo non-diffracting beam (PNDB). The use of such a feature allows avoiding or minimizing adverse effect described above. In combination or to go further than a standard "add value" for near vision, the EDOF customization really allows choosing the length of the depth focus and thus, the distribution of the vision according to the distance.

The EDOF feature is particularly adapted to customize the optical output of the lens to provide a visual acu ity that corresponds to the patient's expectations and way of life. This allows for a progressive vision that can be chosen at defined distances to favor a smooth transition from a reading distance to an intermediate distance for interacting with direct environment (such as talking with people, using a computer, etc.). It allows integrating the accommodation or pseudo-accommodation as a customization parameter for compensating totally or partially the natural accommodation of the crystalline lens.

The present invention concerns on one hand an ophthalmic lens which can be implanted in an eye of a patient to correct eyesight disorder or eye pathology. The invention can also be used in case of cataract surgery, in replacement of the crystalline lens of the patient. On the other hand, the invention concerns a method for manufacturing said ophthalmic lens on demand, according to the patient's characteristics and expectations.

The ophthalmic lens of this invention can be considered as being composed of at least two elements. One of these elements is a base correcting optical element and at least one other element is a phase distribution element. The lens can optionally comprise one or several diffractive structures.

The ophthalmic lens according to the invention is seen as an assembly of these elements. The base corrective optical element is essentially determined so as to take into consideration the type of correction required by the patient and the extent of the correction . The phase d istribution element(s) is essentially determined to take into account parameters related to the type of vision that the patient wishes to have once corrected. The diffractive structure(s) is essentially determined to take into account a desired add value. In the method of the invention , the shape of the base correcting optical element and the shape of the phase distribution element are calculated separately. More specifically, the method comprises a first step in which the needs of the patient are processed, together with biometric information specific to that patient. The processing resu lts in a l ig ht d istribution specification. The biometric data is used to define the shape and other characteristics of the base correcting optical element. The light distribution specification is then used to define the geometrical parameters of a phase distribution element, the shape of the phase distribution element being determined by calculation for generating a light distribution corresponding to the light distribution specification previously defined. Add value can be chosen by determining the shape of one or several diffractive structures.

BRIEF DESCRIPTION OF DRAWINGS

The present invention and its advantages will be better understood with reference to the enclosed drawings and to a detailed description of specific embodiments in which:

- Figure 1 is a block diagram illustrating the method of the invention;

- Figure 2 illustrates a l ight d istribution correspond ing to a patient's expectations;

- Figure 3 is a schematic cross section view of a first embodiment of a lens according to the present invention;

- Figure 4 illustrates light intensity as a function of the power of the lens of Figure 3;

- Figure 5 is a schematic cross section view of a second embodiment of a lens according to the present invention; - Figure 6 illustrates light intensity as a function of the power of the lens of Figure 5; - Figure 7a illustrates a light intensity as a function of the power of a lens having a first extended depth of focus (E-DOF); and

- Figure 7b is similar to Figure 7a, for another extended depth of focus.

MODE FOR CARRYING OUT THE INVENTION

With reference to Figure 1 , the method of the invention is intended to enable manufacturing an intraocular ophthalmic lens. Manufacturing such a lens is based on a calculation of geometric parameters defining the shape of the lens. The method of the invention operates as follows. In a first step, referred to as 100 on Fig. 1 , various features of the patient's eye are determined. These features are among others, biometric information and in particular the type of correction required and the amount or extent of the correction. The type of correction is defined by the type of visual disturbance that the ophthalmic lens of the present invention has to correct. Visual disturbances that such a lens is able to correct include myopia, hyperopia and astigmatism (second-order aberrations). The extent of the correction corresponds to a distant-vision correction . The extent of the correction and the type of correction are generally conventionally used nowadays while correcting a patient's vision. This extent of the correction is used for defining the characteristics of a base correcting optical element.

Other biometric parameters may also be measured and in particular parameters related to dimensions of the eye. These measurements are intended to ensure that the dimensions and shape of the lens are optimal after implantation in a patient's eye.

Alternatively, other characteristics of the eye can be measured. These are for example the aberrations such as spherical aberration, chromatic aberration, or more generally aberrations having an order higher than two. Such aberrations can for example be in the periphery of the cornea and are responsible for the distortion of vision when the pupil dilates. Some visual difficulties these aberrations can cause include halos and glares in the case of night vision. The profile of the higher order aberrations is specific to each eye. These aberrations can be measured and corrected individually by means of the lens of the invention.

A complete biometry of the patient's eyes can be made, which leads to a set of biometric data which is unique and specific for each eye of each patient. This unique set of biometric data can be used for realizing a lens which is unique and specific for each patient. Step 101 of Fig. 1 comprises determining intrinsic parameters of the lens. These parameters are considered as intrinsic as they can be measured or determined from the lens itself.

These parameters can come from different sources. A first source is the biometric data measurements on the patient. The concerned parameters are for example the haptic diameter of the lens which depends on the size of the patient's eye. Another parameter is the lens toricity which depends on the topography of the cornea of the patient's eye.

A second source is the patient's expectations. Typical parameters concerned by this source is the extended depth of focus or the add value. A third source is a choice made by the person in charge of implanting the lens. Parameters concerned are for example the type of haptic or the material of the lens.

More generally, the parameters of the lens are chosen among at least :

• the type of lens (convex, concave, ...)

· the depth of focus

• the haptic diameter

• the toricity

• the extended depth of focus

• the add value

· the material of the lens • the haptic type

Other parameters could also be selected, depending on the implementation.

The result of the step of measuring biometric data specific to the patient and of determining intrinsic parameters of the lens is used to calculate geometrical parameters of the base correcting optical element.

A next step 102 of the method of the invention comprises determining the visual characteristics desired by the patient after correction. These visual characteristics depend in particular on the needs and activities of the patient. For example, for a person who does not drive and reads a lot, near vision will be promoted at the expense of intermediate and distant vision. For a person using a computer frequently, vision at an intermediate d istance will be preferred. In the case of a person driving regularly, for example, distant vision may be favored.

According to an embodiment of the method of the invention, it is possible to define several zones, for example a first zone called near vision zone corresponding to a range typically between 20 and 50 cm from the patient. An intermediate vision zone is defined as covering a range between 50 cm and 1 .50 m, and a third zone, called distant vision zone corresponds for example to a viewing distance extending beyond 1 .50 m. It should be noted that a different number of zones may be defined and/or different distances may be chosen. It is also possible not to separate the viewing distance in discrete zones, but rather to use a continuous distance range.

During this step 102, the user defines his/her needs or requirements related to vision after implantation of the ophthalmic lens. This step is also illustrated by Figure 2. In this figure, three rectangles are shown. One represents the light intensity expected by the patient for near vision; the middle rectangle represents the expected light intensity for intermediate vision and the rectangle on the right illustrates the light intensity expected for distant vision. The sum of the height of these rectangles may represent 1 00% of the available light intensity. As mentioned above, the number of rectangles is not limited to three. It is possible to use only two zones or more than three. It is also possible to replace the discrete rectangles by a continuous zone or curve.

In a subsequent step 103 of the method, the biometric measurements obtained after step 100 and the parameters of the lens obtained in step 101 , as well as the requirements defined by the patient during step 102 are converted into a l ight d istribution specification . Th is l ight distribution specification defines among others, which portions of the available light are allocated to different distances of vision.

Light distribution specifications are at least partially schematically illustrated by Fig. 4, 6, 7a and 7b. More specifically, the curves of Figures 4, 6, 7a and 7b illustrate a light intensity as a function of the optical power of the lens and are obtained by processing among others, the information illustrated by Fig. 2.

An image at infinity focuses on the patient's retina for a lens having a given power (for example 22 diopters). An image close to the patient focuses on the retina for a lens having another power (for example 25 diopters). For a given power, and thus, for a given distance "object side", only a part of the intensity will focus on the retina and will thus be useful "image side". Figures 4, 6, 7a and 7b represent the intensity depending on the power of the lens.

The power required for a given distance depends on the patient and in particular, whether th is patient is emmetropic or not. This information is determined among others during the step 100 of the method of the invention.

It should be noted that there is a one-to-one relationship between the power of the lens and the distance. Thus, it is possible to draw or calculate a curve representing the intensity as a fu nction of a d istan ce from a cu rve representing the intensity as a function of a power. However, as the power is calculated as an inverse of a focal distance, the left and right parts of the curves will be inverted. This means that the left part of the curves of Figures 4, 6, 7a and 7b (low power) corresponds to distant vision and thus, to the right part of Fig . 2. The right part of the curves of Figures 4, 6, 7a and 7b (high power) corresponds to near vision and to the left part of Figure 2. In Figures 4, 6, 7a and 7b, the vertical axis represents the light intensity in percent. The total area of the curve represents 1 00%.

In Fig. 4, a first peak is placed at a first power PF corresponding to far vision distance. In the example illustrated, the intensity at th is first power corresponds to 50% of all the available light intensity. Another local peak is set at a second power PN corresponding to near vision. Finally, the rest of the available intensity is distributed in particular in the intermediate vision so that 1 00% of the intensity is distributed. The curve illustrated by Figure 4, showing the intensities as a function of power, can correspond to the histograms of Figure 2.

Figure 3 illustrates a lens that can be used to produce an intensity distribution as represented on Figure 4. This lens comprises a base optical element represented as a convex lens. The lens further comprises a phase distribution element PDE. This phase distribution element is located at the center of the lens and corresponds to the zone having a diameter D1 in Fig. 3. The shape and size of this phase distribution element influences the extension of the depth of focus. The geometrical parameters of the phase distribution element are calculated from the light distribution specification.

The lens illustrated by Fig. 3 further comprises a diffractive structure DS. This diffractive structure influences the add value. More specifically, the add value is determined by the size (diameter and height) and position of the diffractive structure. In Figure 3, this diffractive structure is illustrated as an annular zone. It should be noted that this diffractive structure can have another shape or that several diffractive structures can be used. The shape and other characteristics of the base optical element define the distribution of the light for distant vision.

The characteristics of the phase distribution element PDE influence the extended depth of focus and the diffractive structure(s) DS essentially influences the distribution of the light for near distance vision. The geometrical parameters of the lens include at least the geometrical parameters of the base correcting element and the geometrical parameters of the phase distribution element. The geometrical parameters of the lens may further include the geometrical parameters of the diffractive structure(s). In Fig. 6, the light distribution curve shows two equal peaks at a first power PF and a second power PN corresponding respectively to far vision and near vision. These peaks are linked by a zone receiving less intensity and corresponding to intermediate vision.

Fig . 5 is similar to Figure 3 and illustrates a lens producing an intensity distribution of Figure 6. Modifications of parameters of the lens such as the diameter shape or size of : the base optical element; the phase distribution element; and/or the diffractive structure(s) influences the light intensity distribution.

As mentioned previously, several parameters are used to define l ight distribution specifications. Among them, two are detailed below. A first one is the add value. This add value indicates how much power is added to the lens to create a near vision zone on the lens. In terms of intensity curves as represented by figures 4, 6, 7a and 7b, modifying the add value modifies the position of the right part of the curve. In other words, the peak referenced as PN can be shifted to the left or to the right by modifying the add value.

Another parameter is the extended depth of focus (EDOF). This parameter defines the extension of the area in which the image is focused.

Figure 7a shows a light intensity curve with a first extended depth of focus (E- DOF = 1 ). Figure 7b illustrates a light intensity curve with a second extended depth of focus (E-DOF = 2), the other parameters of the lens generating these curves being equivalent. As it can be seen by comparing these curves, the peaks corresponding to distant and near vision are in the same positions and have similar intensities for both curves. For the intermediate vision, the intensity is more constant for a lens having a greater extended depth of focus. In the context of this invention, "distribution of light" - which is described and depicted in the examples as a distribution of intensity - must be understood as to be associated with the modulation or contrast of the image formed by the optical system and with the optical resolution. It must be considered that any light distribution or extension of the depth of focus as described herein by an intensity distribution is linked to a contrast performance as a function of defocus (Through Focus Response), which can be interpreted or used in a similar way. Image quality function of object distance is a combination of multiple parameters including, but not limited to, the light intensity distribution and the Through Focus Response.

In a lens with an extended depth of focus, the distribution of light is different from the d istribution of l ight in a conventional lens, "conventional lens" meaning a lens without EDOF. In such a conventional lens, the curve representing light distribution as a function of focal length or power comprises, for each focal length, a relatively narrow and symmetrical distribution around a peak centered at the respective focal length. In the case of a multifocal lens, for example a bi-focal lens, where the focal lengths (of each of the two parts of the lens) are significantly different from one another, the distribution of light may reach zero for a given range of distances, object side. In the case of a lens with extended depth of focus, the distribution of light is not necessarily symmetrical around a peak. Moreover, the width of the light distribution curve is greater than in the case of a conventional lens, this increase of the width taking place at least on one side of the curve, with regard to (at least one) a peak. This extension of the depth of focus can be seen in Figs. 6, 7a and 7b. In Fig. 6, for example, a light or intensity distribution curve for a lens with an extended depth of focus, in which two intensity peaks can be seen at points PF and PN. By way of comparison, a conventional bi-focal lens whose constituent lenses have peak intensities at points corresponding to points PF and PN of fig. 6, intensity peaks would also be seen at points PF and PN, however the i nten sity wou ld d rop off, u n-attenuated, in substantially symmetrical fashion around each of the peaks of the bi-focal lens, leaving a zone corresponding to intermediate vision with little or no intensity at all . Comparing this with fig. 6, it can be seen that for the extended depth of focus lens, significant levels of light intensity are maintained throughout the zone corresponding to intermediate vision. In the curves illustrated by Fig. 7a and 7b, the peaks corresponding to near vision PN are deformed in order to bring light in a zone corresponding to intermediate vision. The resulting light distribution curve is th u s not symmetrical with respect to the axis passing by the point PN and it has been broadened with respect to the peak corresponding to a lens without EDOF. For each zone corresponding to a rectangle in Figure 2, it is possible to define a minimal or residual light intensity. In other words, even if the patient sets the value of the light intensity at one or more of the zones corresponding to near, intermediate or distant vision to zero, a residual intensity will nonetheless reman. Thus, the patient will always receive light and thus, see an image, at any distance.

As it can be seen on these curves, between the minimal and maximal values of power for which some value of light intensity is received, there is no zone (range of powers) for which no light intensity is received. This ensures a more conformable vision to a patient and avoids him/her being "blind" for a given distance of vision without additional visual correction provided for example by glasses. This also avoids, at least to a certain extent, the formation of halos or glares and remedies the problems inherent with multifocal lenses.

According to an optional but interesting embodiment, it is possible to simulate the vision that will be obtained by the patient with the l ight d istribution specifications as defined in step 102 and to allow the patient to test this simulation . This simulation allows the patient to check whether the l ight distribution parameters have been properly selected and if they generate a vis ion correspond i ng to th e expectation s of th e patient. If such correspondence is not met, these parameters can be modified and tested again until the desired vision matches the simulated vision. Th is test is illustrated under the reference 1 04 in Fig . 1 . The test is performed by presenting to the patient, one or several images having objects in different planes . The image(s) d isplay the d ifferent planes with a sharpness corresponding to the sharpness of the vision after correction.

Once the distribution of the light established with or without correction by a simulation, this distribution is used to calculate geometric parameters of the lens in such a way that the assembly formed by the ophthalmic lens and the patient eye leads to the l ight distribution specification as defined in the previous step 102.

A base refractive optical element is defined to get the desired nominal dioptric power of the ophthalmic lens. Additionally, one or several diffractive structures can be used to d istribute the l ight requ ired for other powers. A phase distribution element is used to generate pseudo non diffracting beams (PNDB) to extend the depth of focus, participating in the light distribution. The use of pseudo non diffracting beams enables reaching pseudo-accommodation of the patient's eye. A pseudo-non diffracting beam (PNDB) can be created with a phase mask or phase distribution element that will transform the incident wave front into a beam with a constant intensity wh ile maintain ing a satisfactory resolution along a defined distance on the optical axis.

The beam created is non diverging along a finite propagation distance. The positioning of the PNDB along the optical axis allows distributing light intensity along an extended depth of focus (E-DOF) for an expected visual acuity. Combined with other optical elements of the ophthalmic lens, this type of beam can be used to extend the visual acuity for example from the near vision to the distant vision or even to create a junction between the far and near vision . The beam can be calculated and shifted along the optical axis to provide more or less of a transition between the different vision distances and with more or less overlap between these visions. The beam length (E-DOF) can vary as well.

Definition of the PNDB to extend the depth of focus can be done for example through the parameterization of a radial harmonic function . The radial harmonic function is chosen to be a phase-only filter. Based on the expected depth of focus, the interval where the beam has a near constant intensity on the optical axis is defined and combined with the pupil aperture. This sets the parameters of the harmonic function. This interval can be also shifted along the optical axis to distribute the intensity at the required distance. Doing so, the near constant intensity along a finite distance can be positioned to allocate this intensity in accordance with the desired model. For example, a pseudo- phakic intraocular lens (IOL) with a nominal power P for distant vision can be combined with an add value of +3D for near vision provided either by diffractive concentric circular structures or with a phase distribution element generating PNDB or a combination of both . A phase distribution element generating PNDB can be used to cover the intermediate vision range with an extended depth of focus of some diopters (e.g. 1 , 1 .5, 2, 2.5,...).

In the examples of Figures 3 and 5, a central zone of surface S (e.g. 1 mm ² ) on the optic can be used to allocate intensity for the near and intermediate vision by extending the depth of focus. A second zone with an order of magnitude of 10 ^* S can be used to allocate intensity both for the near and far vision by splitting the intensity. A third zone with an order of magnitude of 20 ^* S can be used to allocate intensity only for the far vision. The intensity distribution resulting from these surfaces is then dependent of the pupillary aperture. The throug h focus response of the optical system must be considered to provide a sufficient resolution for each vision . Any other combination is feasible to reach the expected target and for any intraocular lens type (without limitation regarding the number of zones, the surfaces areas and the use of the anterior or posterior optical surface of the lens). The phase data is converted into geometrical data by considering the wavelength and the refractive index of the lens material by the relation: λΦ(Γ)

t(;r) =

2π(η where λ is the wavelength; Φ is the phase, n is the refractive index of the lens material, t is the height of the phase distribution element and r is the distance to the optical axis of the lens. The surface of each optical element contributes to the required ratio in terms of light distribution or visual acuity.

Different areas can also combine their effects resulting in some overlaps when focusing the light to defined focal lengths to reach the desired intensities at these distances.

The ophthalmic lens comprises an anterior and a posterior surface. Both of these surfaces can be used to distribute the light along the optical axis or to correct visual aberrations by means of multiple optical elements in several zones or surfaces. The base refractive optical element contributes to set the nominal power from its surface curvatures combined with the refractive index of the lens material. The geometrical profiles of the anterior and/or posterior surfaces can be convex, concave or flat.

Additional optical elements can be used on defined zones of the lens to contribute to a pseudo-accommodation by distributing light intensity along the optical axis on the useful region for a natural vision (visual acuity of a healthy eye with accommodation, emmetropic situation). The amount of energy transmitted by the lens for each distance (far-intermediate-near vision) is a function of the surface of each exposed optical element and their intrinsic properties. The conversion of a desired light distribution specification into optical surfaces is therefore dependent on these two aspects. Moreover, the exposed surface of the lens increasing as a square function of the pupil radius, the intensity distribution according to the given model may be set for a standard average pupil (e.g. 3mm) but may also be designed and optimized as a function of the pupillary diameter by lowering any strong visual acuity variation for a rapid diameter change.

From a defined light distribution specification (for example 50% of intensity for far vision, 25% for intermediate vision and 25% for near vision), the surface of each optical element area, combined with its optical properties, is calculated in proportion. The surface allocated for a refractive element can result for example in a 1 00% intensity ratio distributed for the far vision . A surface allocated for a d iffractive optical element such as a d iffraction grating (kinoform , pattern of concentric rings) can be used combined with an anodization model to fine tune the light distribution function of the eye pupil aperture between the far vision and another chosen focusing distance (or more, depending on the diffraction order) by splitting the intensity. Light energy can then be distributed with a ratio that is a function of the pupil aperture to fit the initial desired model. The splitting ratio is mainly driven by the height of the diffractive structures while the added power by their width. Each of these different optical elements has also more or less intrinsic loss of energy that is taken into consideration to reach the desired ratios.

To get the desired light distribution with the expected intensity ratios, the optic includes any (but at least one) optical element that will, depending on its exposed surface and optical characteristics, focus the light collected on this area at a defined distance on the optical axis. Any other optical aberration correction element can be included as a custom- made option.

The method and the lens of the invention enables providing ophthalmic lenses that do not only correct patient's vision diseases, but that are also adapted to the patient's requirements. Moreover, as the lens is custom made, it fits the patient's need in terms of type and extent of corrections of aberrations. This would not be possible in method in which existing lenses are selected.