What is a key feature of a complete cataract?

A complete cataract is characterized by the lens of the eye becoming opaque, leading to significant impairment of vision. When 100% of the lens is affected by opacification, it indicates that the cataract is fully developed, and light cannot pass through the lens, resulting in a substantial loss of vision. This lack of transparency in the lens is what differentiates complete cataracts from partial ones, where some degree of transparency remains, allowing some vision to be retained.

In the context of cataracts, the visibility of the tapetal reflection, the percentage of the lens affected, and the degree to which vision is impacted are all critical indicators of cataract severity. A complete cataract, where the entire lens is opacified, will not allow for any meaningful light transmission, leading to a significant and often total loss of vision.