As time goes on, the body adds on more layers of cells to the lens in the eye that subsequently causes the ‘clouding’ of the lens that is known as the cataract. This can cause reduced clarity of vision, which some people might describe as a ‘foggy’ view, or looking through a dirty windscreen. This is usually an age-related change, and its progression can also be accelerated by exposure to UV and certain medications such as steroids.