legally blind?

[KRB14]

What prescription is considered legally blind? My contact prescription is over -5.00. I am wondering if I am legally blind WITHOUT contacts or glasses.

[Carina_Mone]

Hello,

Last prescription had me at -14.50 D in my left eye and -13.75 D in my right eye.  Cylinder for both eyes, I am not 100% sure but in the vicinity of 4.50, and I do not remember what my axes are.  My vision has not been able to be corrected fully due to complication of keratoconus.  I am concerned because I have had my RGP prescription for six months now and once again am having trouble with road signs and large projector screens in my classes even when sitting in the front row.  I know that keratoconus is degenerative with respect to the cornea, and I need to know what my options are at this point.  And yes, I am aware that LASIX is not an option for me.  Any help you could give is greatly appreciated.

Carina Mone

[zedddy]

OD -1375 -100 30

OS -1600 -150 140

.   sphere cylinder axis

is that blind ?.  

[zedddy]

OD -1375 -100 30

OS -1600 -150 140

.   sphere cylinder axis

is that blind ?.  

[flossy93]

There isn't an exact formula for doing the conversion you requested, esp at higher powers.  

That said, if you are really interested, here is link to a discussion thread on a professional optician message board which gives a guideline to this conversion for lower powers.  This thread also outlines how complicated it is to relate a given Snellen visual acuity measurement (i.e. 20/20) to its 'equivalent' corrective lens measurement (diopters and cylinder prescription).  

http://www.optiboard.com/forums/showthread.php/14648-Diopters-to-Visual-Acuity

[jflatt12]

My son has script of 9.00 +1.75 in his right eye and 8.50 +1.25 in left eye. He is going to see a pediatric ophthalmologist. I was curious just how that prescription is in the 20/20 scale

[John C Hagan III, MD, FACS, FAAO]

1. If you can see with glasses or contacts you are never legally blind with or without them.