# Metric To Snellen VA Conversion Help



## Deleted member 49154 (12 Jun 2012)

Hey guys, I have a hunch that a lot of you med guys are a little tired of seeing (no pun intended) all the "MY PRESCRIPTION is XXX and XXX so am I VX?", but this thing has been bothering me for about a week and I'd be thankful for your help to straighten it out.

I went to my ophthalmologist with the sheet the Senior Medic gives you after they realize your vision isn't quite up to par. I had my eye doctor fill it out and my visual acuity is listed as 60/600 in both eyes uncorrected, 6/6 in both corrected.

Now, after reading that, I realized that my visual acuity is measured under the Snellen system. After reading this :

http://forums.army.ca/forums/threads/31590.0

I understand that the minimum to be a V3 is 6/60, which is equivalent to 20/200 in Snellen.

Now, given my prescription, would I be correct to assume that 60/600 is the same as 20/200? Basically with a little math if I change "60/600" by dividing each side by 3 I would end up with 20/200. I was just wondering that despite the conversion, it would still be accurate with regards to reading it in the metric system. It's a rather straightforward question and I know I seem to be grasping at things that should just be common sense, but for the sake of getting rid of this strange irritation that's been bothering me for the week I'd greatly appreciate your help.

Thanks in advance!


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## Blackadder1916 (12 Jun 2012)

CXCville said:
			
		

> I went to my ophthalmologist with the sheet the Senior Medic gives you after they realize your vision isn't quite up to par. I had my eye doctor fill it out and my visual acuity is listed as *60/600* in both eyes uncorrected, 6/6 in both corrected.



"60/600"!  Your opthalmologist must have a huge office if he had you stand 60 metres (or feet) away from the eye chart.  (_That's sarcasm_).  Are you sure that he wrote "60/600" as your uncorrected VA?  If so, then it is an error.  The first number of a VA is always either "6" (if in metres) or "20" (if in feet - 20 ft equals 6.096 m ), because it represents the standard distance from the chart that the patient stands.  (Yes, the actual distance during the test may be shorter, usually by half, but it is compensated for by using mirrors or charts made for the shorter distance).  You should probably have the ophtho clarify his report before you return it to the recruiting centre.


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## Deleted member 49154 (12 Jun 2012)

Oh boy, now _that_ might be a problem. I sent up the paper almost 3 days ago, and I even gave the Medical Section of the recruiting place a call and they told me that it was sent up to I think. . . Ottawa? I forgot where but it was where the medical reports get officiated and whatnot. I'd imagine that the"60/600" mistake would be a problem? Silly me for taking my ophthalmologists' word in knowing what he was doing. He was former USAF too. Whoo. 

Anyhow, thanks for the response.


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## ModlrMike (12 Jun 2012)

CXCville said:
			
		

> I had my eye doctor fill it out and my visual acuity is listed as 60/600 in both eyes uncorrected, 6/6 in both corrected.



A slip of the pen I think. He probably meant to write 6/60, as he wrote 6/6 for the corrected value.


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## Deleted member 49154 (13 Jun 2012)

Ah okay. Frankly, I wouldn't exactly be surprised if that was the case since before I got there the doctor had quite the scene with an apparently unhappy woman of sorts. Oh well. Shame on me for not noticing the mistake myself. If you were the Medical personnel in charge of reviewing my file and you saw that, what would be the course of action? I'd imagine it could be another month before I'm contacted about the mix-up followed up the necessary steps to fix it, if it needs to be fixed.


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