Pictured here is an example of an opthalmodynamomter dating from 1917. Manufactured by Giroux of France, this instrument would have been used to test the blood pressure of the retinal vessels at the back of the eye. This technique was invented by the French ophthalmologist, Paul Bailliart in 1917. The instrument is a rod-shaped piston with a convex head, which is pressed against the lateral side of the eye with the retina being observed through an ophthalmoscope. The pressure is increased in 10 gram intervals. ]]>