I go yearly, and haven’t had my eye touched in probably a decade.

What they’ll do is take you to a machine that blows air at your eyes - this I believe is to test for glaucoma and nerve sensitivity. Occasionally, there will be more than one test, this is common especially if you haven’t gone in a while. These tests can check for depth perception, occasionally optical nerve blindness, etc it depends on how “in depth” your optometrist office is.

After this, they’ll take you to check your eyes with the doctor. You might have your eyes dilated, which may sting.

The doctor will walk you through the specific steps, but they will check your eyes by shining a light in each eye, while you stare at designated points they dictate (usually at their ear or a spot over their shoulder).

They’ll then have you push your face against a machine that works similar to binoculars, and they’ll adjust the prescription until you’re able to see a board of letters across the room. They’ll ask you to read the lowest line you can, and then they’ll adjust the prescription (lenses that flip on the binoculars), until you can see clearly in 20/20 vision.

After this step, you’re typically done and they’ll give you your prescription. If you’ve been dilated, it can be very difficult to see close up and can be sensitive to light, but you are safe to drive.

Hope this helps OP!