About Lesson
Refraction and Accommodation
Chapter 2 of 5
Refraction
There are 2 main refractive bodies in the eye: the cornea and the crystalline lens. Most of the refractive power in the eye comes from the cornea, due to the differences in the indices of refraction between the air (refractive index of about 1.00) and the aqueous humor, which has an index of refraction of 1.34.
Accommodation
Accommodation is the ability of the lens to change shape and automatically alter focus from distant to near objects. The ability to focus deteriorates over time. Typically, the first signs of deterioration become noticeable around the age of 40 due to a gradual hardening of the crystalline lens, leading to presbyopia.