Donders, Frans Cornelis

born May 27, 1818, Tilburg, Neth.

died March 24, 1889, Utrecht

Dutch ophthalmologist.

His study of "muscae volitantes" (spots before the eyes) resulted in Donders' law, stating that the rotation of the eye around the line of sight is involuntary. His research improved diagnosis, operative treatment, and use of eyeglasses for vision problems. He found that in farsightedness the eyeball is shortened, resulting in light rays being focused behind the retina (1858). His finding that astigmatism is caused by uneven corneal and lens surfaces (1862) created the field of scientific clinical refraction. His On the Anomalies of Accommodation and Refraction (1864) was the first authoritative work in the field.

* * *

▪ Dutch ophthalmologist

born May 27, 1818, Tilburg, Neth.

died March 24, 1889, Utrecht

 ophthalmologist, the most eminent of 19th-century Dutch physicians, whose investigations of the physiology and pathology of the eye made possible a scientific approach to the correction of refractive disabilities such as nearsightedness, farsightedness, and astigmatism.

      Donders' interest in ophthalmology began in 1847 with a study of muscae volitantes, the problem of specks seen floating before the eye. This study resulted in his formulation of what is now known as Donders' law: the rotation of the eye around the line of sight is involuntary.

      As professor of physiology at the University of Utrecht (1852–89), Donders did research that immediately improved diagnosis, operative treatment, and use of eyeglasses to correct impairments of vision. He found (1858) that hypermetropia (farsightedness (hyperopia)) is caused by a shortening of the eyeball, so that light rays refracted by the lens of the eye converge behind the retina. He discovered (1862) that the blurred vision of astigmatism is caused by uneven and unusual surfaces of the cornea and lens, which diffuse light rays instead of focusing them. This last finding created the field of scientific clinical refraction.

      Donders summarized his studies in On the Anomalies of Accommodation and Refraction (1864), the first authoritative work in the field.

* * *