To provide a grinding water processor for a lens grinding device, which can prevent turbidity between used grinding water and filtered grinding water, to thereby achieve sufficient filtering of the used grinding water.

The grinding water processor for the lens grinding device has a grinding water tank 20 in which grinding water for use in grinding eyeglass lenses by the lens grinding device 10, is stored, and a grinding water processing means (filtering device) 40 for filtering the grinding water used in grinding work and separating grinding chips, sediments, bubbles, etc. from the water. The grinding water processor is comprised of circulating means (a filtered grinding water feeding pipe and a circulating pipe) 42, 46 for leading the grinding water used in the grinding procedure to the grinding water processing means 40 without returning the same to the grinding water tank 20, and feeding the grinding water filtered by the grinding water processing means 40 to the grinding water tank 20 or the lens grinding device 10.