Presbyopia is the inability of the eye to focus sharply on nearby objects, resulting from loss of elasticity of the crystalline lens with advancing age.


When you are young, the natural lens and muscles of your eye are able to adjust rapidly and smoothly, allowing you to focus on near-, mid-, and far-range objects.

As you lose some of this natural flexibility, you also lose the ability to focus on near objects: the light rays passing through your natural lens no longer fall on the retina, so the image sent to your brain is fuzzy. This is why you need reading glasses or bifocals.