A cataract is a clouding of the normally clear lens of the eye. When we are young, the natural lens acts like the zoom function in a camera, allowing us to focus up close, without the need for reading glasses or bifocals. As we age, the lens progressively becomes dysfunctional resulting in loss of near vision (presbyopia) that requires the use of reading glasses or bifocals. With aging the natural lens progressively becomes hard, yellow and cloudy, which blocks and scatters light causing blurred vision including unusual glare, poor night vision and a change in how your eyes perceive colors.
To restore vision that has been lost or impaired by a cataract, the cloudy lens must be removed and replaced with a clear artificial lens implant.