MARK THOMAS / SCIENCE PHOTO LIBRARY MARK THOMAS / SCIENCE PHOTO LIBRARY
Historical indentation tonometer. This device was used by William MacLean in around 1918. It is used to measure the intra ocular pressure - the pressure inside a person's eyeball. This is used to help in the diagnosis and evaluation of a number of eye problems including glaucoma. Photographed at the Royal College of Ophthalmologists, London, UK.
Model release not available. Property release not required.