# eli5 glasses prescription purely numbers and signs

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I’m just a bit confused. I’ve found post about glasses perscriptions with names but I’ve just got one with purely numbers and sights l. Reads

+1.75 -2.25 x 179
+3.75 -3.00 x 173

How am I supposed to read and understand this?

In: 2

I am not sur about the order but one is the value of the strength of the glasses, one is for the deformation of the eye and one is (I think) the inner eye pressure.

The +1.75 is a correction do your distance vision. The plus prescription helps far sighted people and vice versa for minus. Think of a magnifying glass just in front of your eyeball.

The -2.25 corrects your astigmatism. Your eyeball is not a sphere so things look less clear. It makes things less fuzzy.

The 179 is the rotational axis that the cylinder curve in the lens is placed to correct the eyeballs aspherical shape.

The left eye is different because your eyes deteriorate over time at separate rates.

The numbers are in two pairs of three values. The first three are for your right eye and the second three are for your left.

The first number is your “spherical correction”, which deals with how close/far things are when you can make them look sharp and clear. A positive number means you are struggling to see things that are close, and a negative number means you are struggling to see things far away. A big number is a big correction and a small number is a small correction.

The second number is your “cylindrical correction” and it means the amount your eye might be too wide or tall. The positive and negatives here don’t matter so much; we can convert them back and forth because saying an eye is “too wide” is the same as saying it is “not tall enough”. A bigger number here means your eye is more like an American football than a basketball.

The third number is the “axis”, which means the direction that your eye is too wide or too tall in. This number goes from 0 to 180, with 0 meaning left-to-right and 90 meaning top-to-bottom. 180 degrees goes all the way around to left-to-right again.

The fourth, fifth, and sixth mean the same thing but for your left eye.

The numbers in your prescription therefore mean the following things

Your right eye is a bit longsighted (+1.75) and is stretched a bit (-2.25). The direction of the stretch is close to left-to-right (x179).

Your left eye is quite a bit longsighted (+3.75) and is stretched quite a bit (-3.00), also close to left-to-right (x173).

All these numbers are pretty normal, especially if you are 40 years of age or older.