How to read eye prescriptions?

Question

I have od: 5.50 os: 5.50 for sphere. For cylinder it is all DS. The PD is 57.5. How can I tell what degree I have totaled for my eyes? Answer?

Answer 1

OD means right eye, OS means left, it means you are equally nearsighted in both eyes, assuming there is a minus sign in front of the number. If its a plus sign that means you are equally farsighted. The PD is the distance between the pupils of you eyes and that's where they set the center of the lenses in your glasses.
The cylinder is usually expressed in numbers not letters. It references the amount of astigmatism.
There is no such thing as degrees in eye measurements, and you don't total the numbers.
From what you gave me, your eyes are about equal, and you need glasses, but you aren't blind.

Answer 2

If you take a lens such as a magnifying lens, it's spherical. That means that if you drew a line across the center like from the 12 to 6, or 7 to 1, or 10-4, or...all the lines would cross in the center and all the lines would have the exact same curve or arc. This lens would focus light at a certain distance from it.

The stronger the lens power, the closer the focal point. The Power of the lens is equal to 1/d where d is in meters.

If this lens focused light at one meter..+1.00
at half a meter +2.00
third of a meter +3.00
eighth of a meter +8.00

You have eyes that are too strong. I'm assuming that the 5.50 is a -5.50 and not a +5.50.

That means that your eyes are too powerful. They are so powerful that you are already focused not at distance, but a fifth of a meter (and a little bit more) in front of your eye. So your own eyes are +5.50 too strong. So they put a lens in front of you to get rid of the power. They give you -5.50 lenses and you can see at distance.

As you don't have astigmatism which would mean that your Rx has two powers, one a little stronger at a certain axis than the sphere. That would look like -5.50 -1.00 x180 or something like that. This would mean that at 180 degrees the power corresponding is 1.00 more powerful than the -5.50. The actual power in that other axis would be -6.50.

If you look at the drug store and see readers that are +3.00, they focus light a third of a meter away or about a foot plus a little more...about 15 inches or so which is normal reading distance.

The PD is Pupil distance. How far is it between the pupil of one eye from the pupil of the other eye? That's the PD.

How well you see when you have your glasses on, that's how good your vision is. so if you see 20/20 with that Rx, you're good to go. Some people see a little better. Most are around that level for most of their lives.

The numbers, the -5.50 are in diopters.
a diopter is.....1/d

Answer 3

Some far East countries use "degrees" to specify eye prescriptions, most other countries use "dioptres". Your prescription is specified in dioptres. One dioptre is the same as 100 degrees.

So you have 550 degrees in each eye.

Answer 4

the sphere is the number of concern, the cylinder and angle you dont nee to know.

Answer 5

ask your optician