What is the visual effect of an incipient cataract similar to?

An incipient cataract is often described as producing a visual effect similar to a smudge on glasses. This analogy is appropriate because an incipient cataract typically causes mild clouding or opacification of the lens, which can slightly obscure vision but does not completely block it. Just like a smudge on glasses can distort vision without entirely obstructing it, an incipient cataract leads to minor visual disturbances such as haziness or a reduction in contrast sensitivity.

The choice to compare this condition to a clouded window or a film over the eyes implies a greater degree of obstruction or less clarity, which does not accurately represent the early stages of cataract formation. A clear lens, on the other hand, would not exhibit any of the visual disturbances associated with cataracts. Therefore, saying an incipient cataract is like a smudge on glasses aligns well with the gradual and subtle changes in vision that occur with this condition.