What is the normal eye power for contacts?

What does Power on a contact lens prescription mean? The power of your lens in measured in dioptres and this indicates the level of correction your lens must provide to correct and sharpen your vision. The correct power should normally give you 20/20 vision.

What does 1.75 mean for glasses?

A -1.75 eyewear prescription essentially signifies that you need some additional power to see some objects that are further away. Specifically, we are talking about things like watching television or objects or people at a distance when you are driving.

Is minus 0.75 eyesight bad?

For both types, the closer you are to zero the better your vision is. For example, even though measurements of -0.75 and -1.25 both qualify as mild nearsightedness, the person with a spherical error of -0.75 is technically closer to 20/20 vision without their glasses on.

What is minus and plus power in eyes?

A “plus” (+) sign in front of the number means you are farsighted, and a “minus” (-) sign means you are nearsighted. These numbers represent diopters, the unit used to measure the correction, or focusing power, of the lens your eye requires. Diopter is often abbreviated “D.”

How is contact lens power related to normal eyesight?

Thus, 20/20 is “normal” eyesight. If, for instance, your ratio is 20/40, then your eye sees the test at 20 feet, where a normal eye could see it at 40 feet, and so on down the list. Therefore, the power of your contact lens essentially tells you the compensation needed for your eyes so that they can see at 20/20.

How to read your power and eye chart?

Hold the page approximately 12-14 inches away from your face. Start reading from top to bottom. Read until you can clearly read a full line. When you can clearly read a full line, look at the associated strength for that line and that is your strength!

What do the numbers on the eye chart mean?

The results are the same whether or not a mirror is used. If you have 20/20 vision, you are considered to have normal visual acuity. The top number refers to the distance in feet that you stand from the chart. The bottom number indicates the distance at which a person with normal eyesight can read the same line you correctly read.

How to read contact lens power ( BC ) and Dia?

The prescription should unfold in the following way: Eye, Power , BC, Dia and Brand. The second 20 is the distance a normal eye can see at the test-20 feet. Therefore, the power of your contact lens essentially tells you the compensation needed for your eyes so that they can see at 20/20.