With the 'dry' form there is a gradual failure of the photosensitive cells of the retina. Sometimes there is a rapid fluid or blood leakage in the macular area which eventually causes disciform degeneration this is called 'wet' degeneration. In general, magnification and high levels of illumination will assist in reading and other near vision tasks. Having cataracts is like looking through a dirty windscreen - if the sun is behind you, your view is reasonably good, but if the sun is in front of you, then your view can be seriously impaired. A cataract is one or more opacities of the crystalline lens.
Cataracts can form at any age, but most often develop as people get older.
In younger people they can be present at birth or result from an injury, certain drugs, radiation or conditions such as diabetes. The opacification of the lens may occur in different ways, so that the light rays which reach the retina may be split, causing multiple images. Age related cataracts are often yellow or brown causing loss of sensitivity to blue. The usual treatment is to remove the lens surgically and replace it with a plastic lens. Because there is no accommodation, spectacles are always needed for some purposes.