Cataracts are a common eye condition. That occurs when the natural lens of the eye is. Becomes cloudy, leading to vision loss. Traditional cataract surgery involves using a tiny blade. To make a small incision in the front of the eye. And a device to make a circular incision in the lens capsule. The cataract is then broken up into small fragments using ultrasound waves. Which are then removed. The natural lens is replaced with a new artificial lens. How to Prepare for Cataract Surgery.