key term - Presbyopia

Definition

Presbyopia is the age-related loss of the eye's ability to focus on nearby objects due to decreased elasticity of the lens. It typically becomes noticeable in middle age.

5 Must Know Facts For Your Next Test

1. Presbyopia occurs because the lens loses its flexibility, making it difficult to change shape to focus on close-up objects.
2. It is a natural part of aging and usually starts around age 40.
3. The condition cannot be prevented, but it can be corrected with reading glasses, bifocals, or contact lenses.
4. Presbyopia affects the refractive power of the eye, which is crucial for focusing light onto the retina for clear vision.
5. Unlike other refractive errors like myopia or hyperopia, presbyopia is not caused by changes in the length of the eyeball.

Review Questions

Related terms

Myopia: A condition where close objects appear clearly, but distant objects are blurred due to light focusing in front of the retina.

Hyperopia:

A condition where distant objects can be seen more clearly than close ones because light focuses behind the retina.

Accommodation:

The process by which the eye changes optical power to maintain a clear image (focus) on an object as its distance varies.