After an eye exam your doctor will hand you a prescription. But have you ever tried to read and understand it?
Ophthalmologists and optometrists sometimes use different measurements for astigmatism. Their prescriptions may appear differently depending on what type of provider you see. The optical shops who make glasses and contacts have no problem reading the prescription no matter who is providing it.
Astigmatism is measured in diopters. A perfect eye with no astigmatism has 0 diopters. Majority of people have between 0.5 to 0.75 diopters of astigmatism. People with a measurement of 1.5 or more often need contacts or eyeglasses to have clear vision.
Of the three numbers on your contacts or glasses prescription, the last two refer to astigmatism: