How do I convert from perscription to x/20 vision?

[Savij]

If my left eye is a -1.00 and the right eye is -1.50, what are the corresponding vision measurements in the x/20 scale?

 

[illusion88]

It doesn't work like that. You need to put on your glasses and go read a wall chart.

 

[Savij]

Originally posted by: illusion88
It doesn't work like that. You need to put on your glasses and go read a wall chart.

What do you mean? I can read all the lines on the wall chart with my glasses on. I thought the point of getting glasses was to be able to read all of the chart instead of only the top line.

 

[George P Burdell]

Originally posted by: Savij

Originally posted by: illusion88
It doesn't work like that. You need to put on your glasses and go read a wall chart.

What do you mean? I can read all the lines on the wall chart with my glasses on. I thought the point of getting glasses was to be able to read all of the chart instead of only the top line.

ALL the lines? If that is correct, in theory you have 20/10 vision.

 

[illusion88]

The wall chart tells you what your vision is rated at based on what line you can raed. That is how you get that number, by the chart not by your prescription.

 

[Savij]

Originally posted by: George P Burdell

Originally posted by: Savij

Originally posted by: illusion88
It doesn't work like that. You need to put on your glasses and go read a wall chart.

What do you mean? I can read all the lines on the wall chart with my glasses on. I thought the point of getting glasses was to be able to read all of the chart instead of only the top line.

ALL the lines? If that is correct, in theory you have 20/10 vision.

That's only with my glasses/contacts on (and when I was a kid i could do the same w/o glasses). Is there no way to tell what my un-corrected vision is w/o going to the eye doctor?

 

[Savij]

Originally posted by: illusion88
The wall chart tells you what your vision is rated at based on what line you can raed. That is how you get that number, by the chart not by your prescription.

Is there no way to get a rough estimate based on the perscriptions?

To enter flight training, a candidate must pass a Flight Class I Flying Physical. To become a pilot, that means the candidates vision can be no worse than 20/70 (correctable with glasses to 20/20) in each eye. To enter Navigator Training, the candidate can have vision no worse than 20/200 in each eye (also must be correctable to 20/20).

 

[Vic]

Generally speaking, -1.00 to -1.50 is in the 20/70 range.

I can't see the big "E" without my glasses/contacts on.

 

[George P Burdell]

Originally posted by: Savij
Is there no way to get a rough estimate based on the perscriptions?

http://www.mdsupport.org/snellen.html

Enjoy. And let us know what your visual acuity is.

 

[Savij]

Originally posted by: George P Burdell

Originally posted by: Savij
Is there no way to get a rough estimate based on the perscriptions?

http://www.mdsupport.org/snellen.html

Enjoy. And let us know what your visual acuity is.

Perfect! Thanks! Now I just need to be able to give myself an eye exam w/o everyone at the office thnking i'm crazy. Neffing is a little easier to hide

 

[thraashman]

Originally posted by: Vic
Generally speaking, -1.00 to -1.50 is in the 20/70 range.

I can't see the big "E" without my glasses/contacts on.

So what would a prescription of -7.00 be approximately? That was what I was before I got LASIK.

Now I'm 20/20 in my left eye and about 20/30 in my right. I think with my glasses I was at about 20/15

 

[jacob0401]

From site that was linked above...

Snellen

20/10
20/15
20/20
20/30
20/40
20/50
20/100
20/200

Estimated prescription

Plano (zero)
Plano
Plano to -0.25
-0.50
-0.75
-1.00 to -1.25
-1.75 to -2.00
-2.00 to -2.50

 

[SoulAssassin]

I just asked my g/f what her prescription is out of curiosity...5.5 or 5.75 in one eye and 4.75 in the other. HFS...she has to be bordering on legally blind.

edit: looks like 20/200 is legally blind so she's way over that.
http://www.medterms.com/script...t.asp?articlekey=10614

 

[davestar]

Originally posted by: SoulAssassin
I just asked my g/f what her prescription is out of curiosity...5.5 or 5.75 in one eye and 4.75 in the other. HFS...she has to be bordering on legally blind.

edit: looks like 20/200 is legally blind so she's way over that.
http://www.medterms.com/script...t.asp?articlekey=10614

i assume you realize that 20/200 with corrective lenses is the definition of legally blind?

 

[Savij]

Ok, so I looked at the chart, but I'm a little confused on how to read the results as x/20. I could consistently read the PNTUHX line with my good eye and combined eyes. My bad eye was at the HZP line. With glasses I can read the second to last line and about 50% of the letters in the last line with with combined vision. Single eye was at the nph... line with either the left or the right eye.

 

[Savij]

Bump on how to read the chart.

 

[dullard]

Originally posted by: Savij
Bump on how to read the chart.

Wikipedia has the chart with 20/20 type numbers marked.. No need to redo it, just use the same line on both.

 

[George P Burdell]

Originally posted by: dullard

Originally posted by: Savij
Bump on how to read the chart.

Wikipedia has the chart with 20/20 type numbers marked.. No need to redo it, just use the same line on both.

As long as you can read the line labeled 6, you're good to go.

 

[ALAUSA]

I have prescription and want to convert them into one eyeglasses

SPH CYL AXIS
+1.5 - -
+1.5 - -


0 -0.75 70 ADD +1.5
0 -0.75 70 ADD +1.5

Any help ?