A cataract is any opacity in our natural lens. You would think that opacity in the lens will cause visual problems but that is not entirely true. There are many types of cataracts, some affecting your eyesight very slowly but others, much faster. A cataract only needs surgical removal if it affects your eyesight significant enough to interfere with your daily living.

Normal Lens - light focus on retina clearly	Cataract lens - light hardly focus on retina