Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ski.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!qantel!ptsfa!ski!dr From: dr@ski.UUCP (David Robins) Newsgroups: net.med Subject: Re: Radial Keratotomy -- WARNING!! -- Message-ID: <212@ski.UUCP> Date: Mon, 11-Nov-85 15:13:41 EST Article-I.D.: ski.212 Posted: Mon Nov 11 15:13:41 1985 Date-Received: Wed, 13-Nov-85 07:19:54 EST References: <203@bnrmtv.UUCP> <419@graffiti.UUCP> Distribution: net Organization: Smith-Kettlewell Institute, S.F., CA. Lines: 34 > > resultant far-sightedness may need to then be treated. > > A lot of people, particularly short-sighted people, tend to get more far > sighted as time goes by anyway. Have the studies corrected for this (probably, > but it's best to be sure)? Near-sighted people do *NOT* become far-sighted at time goes on. They do become presbyopic, as everyone does as they get older (past 40 or so), but this does not alter their distance refraction. Presbyopia is age-related decrease in accommodation, or ability to focus the eyes from the relaxed distance focal point, to the accommodated near focal point for reading. Near-sighted (myopic) persons often become presbyopic at a later age than normal (emmetropic) persons. In addition, if someone is very myopic, the minus lens they wear slightly decreases the accommodation needed for a given near distance, due to the optics involved. {Presbyopia is when one has trouble reading at the normal reading distance, but can read by holding the material farther away (at least until one's arms cannot hold it far enough away for comfort)!}(get longer arms? (:-). The R-K studies follow the distance correction, which is a function of the optics of the eye, rather than the accommodative reserve. -- ==================================================================== David Robins, M.D. Smith-Kettlewell Institute of Visual Sciences 2232 Webster St; San Francisco CA 94115 415/561-1705 {ihnp4,qantel,dual}!ptsfa!ski!dr The opinions expressed herein do not reflect the opinion of the Institute!