Myopia: its historical contexts

Abstract

Worldwide, and especially in Asia, myopia is a major vision-threatening disorder. From AD 1600 on, to prevent myopia, authors warned against near work without sufficient pauses. There was an abundance of theories about the causes of myopia, the most common one being the necessity of extra convergence on nearby work with thickened extraocular muscles and elevated intraocular pressure. Ocular tenotomies against myopia were in vogue for a while. Axial lengthening of the eye in myopia was mentioned around 1700, but it took 150 years to become accepted as the most prevalent sign of high myopia. In 1864, a lucid concept of myopia and other ametropias arose through a clear separation between accommodation and refraction. Posterior staphyloma was known around 1800 and its association with myopia became evident some 30 years later. There still seems to be no generally accepted classification of myopia and particularly not of degenerative or pathologic myopia. This review focuses on myopia from 350 BC until the 21st century and on the earliest writings on the histology of eyes with posterior staphyloma. A proposal for myopia classification is given.

Keywords: accommodation; history of myopia; myopia classification.

Figure 1

(A) Explanation of Claudius Dechales concerning how a pinhole improved far vision in his myopic eye. Without a pinhole, the image covers the area on the cornea with a diameter MI, with a pinhole KO and thus the image seems smaller with a pinhole. “A pinhole can also improve vision in elderly persons even when their rays converge behind the retina. By squeezing the eyelids, the vertical distortion is more diminished than the horizontal one. Because some lashes are placed in front of the pupil, multiple horizontal pinhole images are formed, of which often one seems the clearest”. (B) The beam path through a convex (left) and concave lens (right).

Figure 2

(A) Crescentic, strongly reflecting surface C, immediately distinguishing myopia on ophthalmoscopy. On the right, a selection of sketches by Donders of the various types of cones he saw in 1500 myopic patients, published 13 years after the invention of the ophthalmoscope. (B) 1. Glaucomatous optic nerve excavation and posterior staphyloma. 2. Medium-sized ‘conus’ in an eye that was myopic due to posterior staphyloma. 3. Very large conus in an eye that was myopic due to posterior staphyloma. 4. Double conus in an eye that was myopic due to posterior staphyloma.

Figure 3

Scleral protuberance (b) in a sheep fetus which would be the weak spot leading to posterior staphyloma.