Can someone help me understand my eye glasses prescription?

Question

OD:

Sphere:

+.50

Cylinder:

-1.75

Axis:

002

OS:

Sphere: +0.25

Cylinder:

-1.75

Axis:

169

Answer 1

Dr. Dolittle did get it all wrong.

OD = ocular dexter = right eye.

OS  = ocular sinister = left eye.

You didn't say how old you are but I would be willing to bet that if you are under 30, you probably think that you see fairly well without any correction at all - probably slightly better with your right eye then your left eye, and definitely better at near than at far.  The reason you are not in focus is primarily due to astigmatism (overall you are slightly nearsighted).  This type of blur affects all distances - far, close, and everything in between.  Although you may see fair without correction, forcing yourself to see through the uncorrected astigmatism "strains" your eyes and you will probably feel the strain on your eyes (and possibly headache) when not wearing your prescription, especially if you spend any time on a computer or do any detailed near work.

Sincerely,

Dr. Maller

Answer 2

Dr. Dolittle sure screwed that up...nothing is right...lol

OD is right eye...

You have slight nearsighted correction, the + 0.50

Then your astigmatism correction is the - 1.75

The axis is just the angle that the -1.75 is ground at in your lenses.

OS is your left eye...the same thing applies as on the right , minor farsighted, same astigmatism, but ground at axis 169.

The axis has no power, it can't be good or bad...it is just the direction that the astigmatism correction is ground at in your lenses.

Answer 3

neither eye is "nearsighted" nor "farsighted".  both are "mixed astigmatism"

Answer 4

OD = right eye

OS = left eye

the small amount of "+" sphere part of your prescription means that you are slightly farsighted in both eyes.  ie. you can see better at distance than you can at near.  

the cylinder part of your perscription signifies the amount of astigmatism for which you are being corrected.  astigmatism is a correction for extra curvature which the front surfact of your eye has...that causes light to defocus as it enters your eye.

the axis is describing the direction at which your astigmatism needs to be corrected.  If you break the eye up into 360 degrees, the axis number lets the optical know at which degree your lens needs that extra correction added.

hope that makes sense!

Answer 5

Hello,

I'm afraid eyes come with a really long set of medical technical words.

A glass lens that concentrates light to a point, like a magnifying glass you can use to start a fire, is called a 'plus' lens, or '+'.  The number that follows it is the strength of the lens to do this, and is measured in units called 'dioptres,' (or spelled 'diopters'), there is no common word.  And the dioptres number is expressed in decimals too, sorry.

So +0.50 means a magnifying lens of .5 (half) a dioptre.  The +0.25 means that this magnifying correction lens isn't as strong, it's 0.25 (a quarter) of a dioptre.

A 'minus' (-) lens does not concentrate light, it spreads it apart. This is the sort of lens also used in some sorts of telescope.  -1.75 means a diverging lens of one and three quarter dioptres.

These lens numbers do not express what is wrong with your eyes, at least not directly.  They express what is wrong in terms of what type and power of lenses are needed to *correct* what is wrong.

In general, plus lenses are needed to correct long sight,and minus lenses are needed to correct short sight problems.  Long sight is where you can see far away just fine, without glasses; near sight is where you can see close-up things just fine, without glasses.

In perfect-sighted people, the clear curved opening at the front of each eye is perfectly curved in all directions.  However, if this front curve is  not quite perfect in all directions, the imperfection is called 'astigmatism' (pronounced ay -STIG'' - matt - izm).

On your prescription, the 'axis' expresses which direction the curved imperfection at the front is, in degrees like on a compass.  So one axis is at two degrees (002) which is almost due north-south, and the other axis is at 169 degrees, which is about south-south-east/north-north-west.

Because for each eye, the plusses and minusses are mixed, you could say that you have a mixture of mild eye problems, which a mixture of lenses will correct.

Hope this is of some help.

Best wishes,  Belliger (retired uk gp)