Simply put, the refraction is the part of the eye exam in which we determine your eyeglass prescription. AKA the better-one-or-two part. Traditionally, we actually perform two refractions . . . objective and subjective.
The objective refraction can be done manually with a hand-held instrument or by machine . . . automated is what we like to call that . . . performed by a technician during pre-testing. Either way, you don’t have to say a word as we measure what it takes to focus distant light rays onto the retina – the length of your eyeball(s). Why is this done? One, it gives the doctor a starting point – a ballpark measurement – from which to perform the subjective refraction. Two, assessing the light reflecting off your retina is one way to check for cataracts; and three . . . , well this is now sounding like a boring board exam review, so two reasons are all you need. Trust me!
The subjective refraction is where you get involved, and it’s really cool, because what the doctor is measuring is NOT your eyeball but actually how your BRAIN “sees” the chart . . . ewwwwwww . . . is right. This is the which-one-is-better-one-or-two part that some people either love or hate. Love because dang that chart is clear! Hate because dang I think I failed! And it is true . . . you could zig, when you should have zagged. But remember, it’s you and the eye doctor that are doing this together. SO, an astute eye doctor will take the time to double or even triple-check that you’re not straying into refraction no-man’s land, and keep you on the straight and narrow towards your best spectacle prescription.
Ask any eye doctor, and they’ll tell you that performing a refraction, determining your visual correction, is an art form. Heck, one of the must reads of any optometry student or ophthalmology resident is The Fine Art of Prescribing Eyeglasses Without Making a Spectacle of Yourself by Milder and Rubin. It’s been around forever. Check out the cover, you’ll see what I mean.
No two people are alike. We all have unique demands on our vision; Each of us has a different tolerance to blur. So, eye doctors are continually looking at the whole picture . . . your current glasses, your visual difficulties, how you use your eyes, the results of the objective and subjective refraction, the status of your eye health, how your eyes coordinate together . . . and come up with a final eyeglass prescription.
Like any form of art, beauty is in the eye of the beholder. When you put the new glasses on for the first time, yes . . . you will have to adapt, but yes, you should be able to see as clearly as you possibly could. But, let’s say you did zig when you should have zagged, and you did end up in eyeglass no-man’s land. You gave the glasses a fair chance, and you still are not satisfied with your vision. Go back and do it again. Eye doctors would actually prefer that. It happens. In fact, the industry is built to accommodate this problem. We call it a “RE-DO” policy. The optical labs and suppliers, vision insurance plans, eye doctors all have allowances to re-do the glasses if need be without any further financial obligations on your part. No worries.