This day in tech 1850, the eyes have it- ophthalmoscope developed

1850: German physician Hermann von Helmholtz, who devoted much of his career to studying the eye and the physics of vision and perception, demonstrates his ophthalmoscope to the Berlin Physical Society. The invention revolutionizes ophthalmology.

Although von Helmholtz was not the first person to develop an ophthalmoscope, nor the first to examine the interior of the eye, his device was the first to be put to practical use.

The ophthalmoscope allows the examining doctor to look inside the patient's eye at the lens, retina and optic nerve. It is the indispensable tool for diagnosing diseases of the eye, including glaucoma, and is used to screen for diabetic retinopathy, a condition in diabetics that can result in blindness. Caught early enough -- and the ophthalmoscope is the method for pinning it down -- the condition can be treated with laser surgery.