Antique Spectacles David Fleishman, M.D., a retired ophthalmologist, has compiled a rather extensive collection of information about spectacles and their importance in history. In addition to many examples of early spectacles and information about the spectacles worn by figures in history, there is a general history - Eyeglasses Through the Ages:[R]eading glasses are one of the most important inventions of the past 2000 years.... No one really knows about the early history of image magnification. In ancient times, someone noticed that convex-shaped glass magnified images. Sometime between the year 1000 and 1250 crude technology began to develop regarding reading stones (simple magnifiers). English Franciscan Friar Roger Bacon (1220 -1292), in his 1268 ‘Opus Majus’, noted that letters could be seen better and larger when viewed through less than half a sphere of glass. Bacon's experiments confirmed the principle of the convex (converging) lens, described by Alhazen (965-1038) Arabian mathematician, optician and astronomer at Cairo, and even earlier by the Greeks. (via the dead tree version of the WSJ)
posted by caddis on Apr 6, 2006 - 18 comments

Medical professionals are supposed to tell the truth. But why do they always lie?

I had an exam yesterday and they lied to me again as they always do.

Every time they do the glaucoma test, I have been told that they will get "close" to the eye. I correct them and tell them, no, you're going to touch it. They'll deny it 3 or 4 times before finally conceding that they'll "barely touch it" or something like that.

"The most common way to currently measure pressure inside the eye is tonometry. In air tonometry, a short burst of air hits the cornea. In applanation tonometry, a doctor anesthetizes the eye, then presses against it with a tiny instrument and measures the depth of the indentation." (sorry-- this is where I got the quote-- it's mostly about something else-- even web pages are reluctant to admit they'll touch your eyeball).

I have never recieved air tonometry, it's rarely used and considerred inaccurate.

This only bugs me because years ago a doctor told me he was going to get close to my eye, I could feel him on the surface through the aneshthetic and pulled back. This happened repeatedly. Eventually he told me he had to touch the eye. If he had told me that in the first place, I wouldn't have thought he was screwing up and I wouldn't have pulled back.

Well ok, it also bugs me that a doctor would utter such an obvious lie (you can feel them on the eye and see the cornea distort when it's pressed). What else are they lying about? What are their motives? (I have contacts, I touch my eyeballs all the time, surely they don't think I have an eyeball touching phobia...)
posted by squinky on May 31, 2002 - 31 comments