The lens is able to refract light because its index of refraction-normally about1.4 centrally and 1.36 peripherally-is different from that of the aqueous and vitreous that surround it. In its non-accommodative state, the lens contributes about 15-20 diopters [D] of the approximately 60 D of convergent refractive power of the average human eye; the air-cornea interface provides the rest, or 40-45 D. The aim of this essay is to discuss the optical properties of ideal intraocular lens for cataract surgery patients that meet their visual needsCataract is the most leading cause of blindness in the world. Treatment of cataract is done by its surgical extraction. In the past, cataract surgery patients were left aphakic and that was associated with many drawbacks of aphakia correcting glasses.