What's this P1 in my eyeglass prescription?

April 23, 2007 12:13 PM

I am the newest member of the eyeglass-wearing community (or I will be when they get here in 5-7 days) and I have a question about my prescription.

Thanks to this Wikipedia article I can read my prescription, except for one detail. Here's my prescription, and the part I don't understand is bolded:

OD p1 -.50 x 115
OS +.25 -.75 x 040

I'm not sure that it is a P1 or PL - which is it and what does it mean? As I understand it from the Wiki article, that is the spherical for my right eye (though my prescription doesn't have that nice chart the one in the article does.)

posted by IndigoRain to Health & Fitness (5 answers total)

Best answer: From the article you linked:

When no correction is needed, the spherical power will sometimes be written as "0.00" and sometimes as "Plano" or "Pl" because the lens, although not flat, is optically equivalent to a flat piece of glass.

posted by cerebus19 at 12:27 PM on April 23, 2007

Best answer: three types of eye correction

for short sightedness,

for long sightedness,

and for astigmatism, the spherical stuff.

I'm guessing you got a combination prescription which includes correction for a minor astigmatism [the wiki article doesn't mention this word at all]
posted by infini at 1:14 PM on April 23, 2007

Best answer: Infini, astigmatism is corrected by the cylindrical correction (the second number in each row), not the spherical correction.

As cerebus19 noted, the mark in question is a PL and stands for "plano," a shorthand way of indicating that the spherical for that eye is zero. This just means that your right eye doesn't need any magnification, only a slight directional blur adjustment for astigmatism.
posted by zadermatermorts at 1:59 PM on April 23, 2007

Response by poster: D'oh. I should have read the article more thoroughly. Thanks.
posted by IndigoRain at 2:18 PM on April 23, 2007

thank you zadermatermorts, I was going by pure guesswork based my own prescriptions and how they've changed to accomodate the changes of increasing astigmatism in addition to myopia over the past 32 years.
posted by infini at 2:40 PM on April 23, 2007