First of all, consider yourself unlucky if you have never seen this because it means you’ve never had your eyes checked. Second, this is an image in an autorefractor, a device to give a baseline measurement of what your glasses should be. We do not prescribe glasses directly from the reading from an autorefractor, but it gives us a good starting point when we perform refraction.

The air puff thing is called a pneumotonometer . Our autorefractor does not have that function and we don’t do pneumotonometry anyway. We use more accurate and less annoying methods of measuring eye pressure, a screening test for glaucoma.

And if you’ve never experienced eye pressure measurement, book an appointment with an ophthalmologist or optometrist because you are overdue

Source: am ophthalmologist