What does 20/20 vision mean? 20/20 vision is normal vision acuity (the clarity or sharpness of vision) measured at a distance of 20 feet. If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at a distance.

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This is what they all mean:

1. ‘+’ or ‘-‘ ‘+’ – Shows if you are long sighted (longsightedness)
2. SPH or Spherical number. This shows how strong the correction needs to be.
3. CYL or Cylinder number. This shows how much astigmatism you have and the number can be negative or positive.
4. AXIS.
5. PD or Pupillary distance.
6. ADD.
7. PRISM.
8. BASE.

Normal vision occurs when light is focused directly on the retina rather than in front or behind it. A person with normal vision can see objects clearly near and faraway. Nearsightedness results in blurred vision when the visual image is focused in front of the retina, rather than directly on it.

Normal eyesight falls between 6/6 and 6/15. Higher numbers represent weaker eyesight. 6/6 – 6/9 is normal vision, no glasses needed. If your vision is less than normal, consult an eye specialist at Al-Shifa Trust Eye Hospital.

20/10 vision is thought to be the maximum visual acuity of human eyes without binoculars or other magnifying devices.

This is a fairly mild amount of nearsightedness. If you are -4.25, that means you have 4 and 1/4 diopters of nearsightedness. This is more nearsighted than -1.00, and requires stronger (thicker) lenses. Similarly, +1.00 would be a small amount of farsightedness and +5 would be more.

“Normal” vision is 20/20. This means that the test subject sees the same line of letters at 20 feet that person with normal vision sees at 20 feet. 20/40 vision means that the test subject sees at 20 feet what a person with normal vision sees at 40 feet.