I’ve been through it several times and I still flinch every time but by then, the machine’s laser detectors will have measured how much the eyeball deformed from the precisely controlled puff. Too little indicates a problem that could lead to glaucoma (vision tunneling).
The procedure used to be way worse, the patient would lie down and have ACTUAL WEIGHTS lowered ON TOP OF THE EYEBALL. Of course, they would need to remain still an open-eyed throughout.
Look up indentation (Schiøtz) tonometry. In Eastern Europe, applantation tonometry was developed and used around that time, where the patient was sedated with cocaine and a known-weight cylinder covered in hydroglycerinated Bismark brown solution (basically eye-safe ink) was placed on top of the cornea. Part of the cornea that pressed flat against the tool displaced the ink, which was then stamped on paper to measure the white circle.
Non-contact tonometry was first developed in 1972 by Dr B. Grolman and didn’t change much since except now it’s digital of course.
I’ve been through it several times and I still flinch every time but by then, the machine’s laser detectors will have measured how much the eyeball deformed from the precisely controlled puff. Too little indicates a problem that could lead to glaucoma (vision tunneling).
The procedure used to be way worse, the patient would lie down and have ACTUAL WEIGHTS lowered ON TOP OF THE EYEBALL. Of course, they would need to remain still an open-eyed throughout.
Do you have a source for that? Sounds crazy. At least today you can alternatively measure it with eye drops and a special optical instrument
Look up indentation (Schiøtz) tonometry. In Eastern Europe, applantation tonometry was developed and used around that time, where the patient was sedated with cocaine and a known-weight cylinder covered in hydroglycerinated Bismark brown solution (basically eye-safe ink) was placed on top of the cornea. Part of the cornea that pressed flat against the tool displaced the ink, which was then stamped on paper to measure the white circle.
Non-contact tonometry was first developed in 1972 by Dr B. Grolman and didn’t change much since except now it’s digital of course.
Damn that is rough, thanks for the reference. Really glad I was born when I was 😅