Different machine, at least in my (unfortunately extensive) experience. The inner eye pressure tester has just a dot, no picture. And it's not that bad, very treatable. But if you miss it too long, yep your blind

[–] joyjoy@lemm.ee 3 points 1 month ago (1 children)

The eye pressure test stresses me out.

[–] ChaoticNeutralCzech@feddit.org 4 points 1 month ago (1 children)

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.

[–] mormund@feddit.org 2 points 1 month ago (1 children)

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

[–] ChaoticNeutralCzech@feddit.org 3 points 1 month ago (1 children)

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.

[–] mormund@feddit.org 2 points 1 month ago

Damn that is rough, thanks for the reference. Really glad I was born when I was 😅

[–] Cenotaph@mander.xyz 3 points 1 month ago

That or you were holding your breath in anticipation of the puff lol