So, your neighbor just had his cataract removed.
Cataract surgery is performed when the lens of the eye, which focuses light rays, becomes cloudy.
When it interferes with vision, it is called a cataract and the treatment is to remove the cloudy lens surgically. The natural lens has a clear, cellophane-like outer shell called the capsule. The most common method of cataract surgery leaves the back or posterior part of the capsule intact after the rest of the lens is removed. This technique maintains the normal barriers between the inside compartments of the eye. The back part of the capsule is used to support the intraocular lens implant, usually inserted at the time of cataract surgery.