YAG capsulotomy is a laser eye treatment. It is done to improve your vision after cataract surgery. Your vision can become cloudy again after cataract surgery. This is sometimes called an after cataract or a secondary cataract. But it isn't a new cataract. Instead, your posterior capsule, which holds the lens in place, becomes cloudy. Your eye care provider may do a YAG capsulotomy to help you see better.

When your cataract is removed, your eye's cloudy lens is replaced with a new clear plastic lens called an IOL (intraocular lens). The IOL is placed in the posterior capsule, which held the old cloudy lens. Your vision improves because the IOL lets light reach your retina. The retina is a tissue layer that lines the back of your eye.

The posterior capsule is a thin, clear film. It can become cloudy. This can happen months or even years after cataract surgery. This may block light from reaching your retina.