What is a cataract operation?
What people call a "cataract operation" is actually the removal of the normal and natural lens of the eye and its replacement with a new, artificial lens implant (an Intraocular Lens or IOL). The reason to do the surgery is usually because the natural lens you are born with tends to degenerate with time and may become cloudy and hardened. The reason for the lens implant is that a "cataract" is nothing more than an aged or dysfunctional lens (it is not a "skim" or a "film"), so removing the old lens without putting a new one in its place would create an unacceptably thick pair of glasses to fix.
While cataract/IOL surgery is extremely successful with a very high degree of accuracy, this does mean it is risk-free. While very, very rare, there could be infection, exaggerated inflammation, hemorrhage (bleeding), and the IOL could dislocate. While these complications are usually treatable, in an extreme situation, it is possible to suffer a severe and devastating loss of vision, scary as that may sound!
J.Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic