What is the cause of a cataract?

Cataracts are primarily characterized by the clouding of the natural lens in the eye. This clouding occurs when proteins in the lens begin to break down and clump together, forming cloudy areas that interfere with light passing through the lens and thus impairing vision. Factors such as aging, sunlight exposure, and other medical conditions can contribute to the development of cataracts, but the fundamental issue remains the opacification of the lens itself.

Infection in the eye, blockage of the optic nerve, and damage to the retina, while related to various visual problems, do not cause cataracts. These conditions involve different mechanisms and areas of the eye but do not lead to the clouding of the natural lens, which is specific to cataract formation. Understanding the specific role of the lens in cataract development is important for recognizing how this common eye condition occurs and its implications for vision health.