How to read eye exam results?
by Adrian
(USA)
Sample Eye Test Prescription
Question: I had my eye exam today and got a copy of prescription. But what do the numbers mean?
Answer: Hi Adrian, This is a common question. To answer it clearly, let's look at an example.
In the picture you can see a sample prescription. The first row is labeled "Sphere". It records whether you are short-sighted or long-sighted and by how much.
In this example the person is longsighted, indicated by the plus sign (+) in front of the numbers. You can see that the left eye is more longsighted than the right eye, by the larger number. Short-sightedness is indicated by a minus (-) sign.
The "Cylinder" row indicates that this person has astigmatism. In the right eye the amount is -1.00, with a smaller amount of -0.50 in the left eye. This happens when the eye is not perfectly spherical. (Around 40% of eyes have this)
The "Axis" indicates the orientation of the astigmatism in degrees. (eg 90 degrees is vertical)
The "Add" shows how much extra power is required for reading at close distances. This is in addition to the main prescription. The main people who need this are the over 40 year olds. The condition is called Presbyopia.
