The lens is responsible for focusing light on the retina, the light-receptive tissue that lines the back of the eye. In a normal healthy eye with a clear lens, light passes unobstructed through the lens to the retina. The retina then converts the light into neural signals that are sent to the brain. In order for the brain to receive a sharp image, the lens must be clear.
Consequently, people with cataracts often experience blurry vision over time as their lens gets cloudier. Additionally, cataracts due to age can cause discolouration of the lens from clear to a yellowish or brownish hue. This change in colour may result in a change in colour perception. Other symptoms of cataracts include glare, difficulty with night vision, poor vision in low lighting conditions, and double vision occurring in one eye.