Eye exam, Refraction

Why the eye doctor says "1...2...1...2..."

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People & Blogs

Tags:

• eye exam
• refraction

[squelch9]

The JCC explanation is pretty vague and confusing, don't ya think, doc? From what opto school did you graduate?

[justinsparhawk]

@squelch9 If you know what a Jackson Cross Cylinder lens is, you know more than most My videos are not instructional for people studying optometry or optics, they are for people curious about their eye exam and what to expect. If you want a description of of the JCC, go back to class or pick up a copy of Borish's Clinical Refraction. I graduated from the New England College of Optometry.

[KristineMendoza13]

Sorry to say this but this OD creeps me out

[justinsparhawk]

@KristineMendoza13 Happy to oblige

[lenoat702]

Can you have glasses that make your vision better than 20\20?

[justinsparhawk]

@lenoat702 If your eyes and brain have the capacity to distinguish detail smaller than 20/20 then yes, you should see better than 20/20. It is quite common actually.

[Remington1875]

I thought one was better than two.

[igykalen]

My first eye doctor when i was a little kid was a fast talking Indian who would say "this or this, this or this, this or this..." way to fast for me to focus on either one and I'd say 'this' as he was changing it and he would move on to the next thing.

That was somewhat disconcerting.

[aurora9702]

Thanks for showing us :D

Never tries one of those machines~

[salmanc1]

This is excellent information

[OxMarissa5x3]

so if i don't know the difference between one & two does that mean i don't have estigmatism? last time at my eye exam i really couldn't tell the difference but i still picked a number i thought was best cus i didnt think them being the same was an option.. it was just confusing

[frontliner0]

Eye exams r the best, they trigger my ASMR (google it).. Soooooo goood

[Pullisto]

Hi, can you please give me a conversion of what -6 is in the measurement of 20/XXX or 6/XXX is? I know what these measurements mean, where as -6 gives no real perspective. My partner is nearsighted -6, and can only see clear 25-30cm in front if without glasses on. But even so he seems to not see that well, even in this short field, has to read a large, lit mobile phone screen with 1cm fonts at only 2cm to see it, without glasses on. Of course at this distance had to look at it from one eye.

[fernandatralala]

I love making eye exam. I love the sound of the machines... :)

[IBMaccMartelli]

Finally I've been wanting to know how this thing worked. Now I know and it's not all "1 and 2" there's really some numbers there. Optometry is cool.

[otissumnerbrown]

@lenoat702 Yes! In fact some retinas have the capability of 20/18 and 20/15. The OD will prescribe for Best-Visual-Acuity -- so you automatically get the "Best" vision through a strong minus lens. Some ODs will not over-prescribe like this, but will provide a lens that gives you 20/20. The difference can be 1/2 to 3/4 diopters.

[tkdkicks2001]

Very informative. Thank you!!