Far, far back in the stygian mists of time (30 years ago), cataract surgery was a major inconvenience. Patients required a prolonged hospital stay and often had to lie still for many days. Then, after the bandages were removed, they would have to be fitted with contact lenses or very thick glasses.The glasses were unsightly and caused all sorts of unwelcome distortions, but were necessary because the cataract removal put the eye way out of focus. The cataract develops in the lens of the eye, and the lens accounts for about 1/3 of the eyes focusing power.Therefore, when its removed, the eye is very much out of focus. What an ordeal!
You and I are lucky to be living in a far more civilized age. Now all we have to do is replace the troublesome lens of the eye with a small plastic lens that stays in the eye permanently. The new lenses are very safe, so much so that cataract operations are now rarely done without one.But one problem remains: the lenses dont completely correct distance vision and people need reading glasses.
If this were a movie, this is precisely when a multifocal intra-ocular lens (IOL for short) sweeps down from the heavens in a cape to save the day and banish evil and so forth. These IOLs are good for both reading and distance vision, which means that combined with surgery for astigmatism, patients with IOLs can be freed of glasses for 80% of their activities. For long periods of reading, a small correction may be needed.
The only downside of multifocal IOLs is the fact that people will notice rings around lights at night due to the shaping of the lens. Most people get used to this, and the benefit of being able to function without glasses is more than adequate compensation. It certainly beats what youd have to put up with 30 years ago!