What does it mean to have 20/20 vision?

People with 20/20 vision have normal vision. This does not mean that your vision is perfect, but you can see an object clearly at a distance of 20 feet – the same distance other people with normal vision can clearly see the object. 20/20 vision describes visual acuity, or the sharpness of vision at 20 feet from an object. Having 20/60 vision means that you must be at 20 feet to see what a person with normal vision can see at 60 feet. Though people with 20/20 vision can see clearly, this measurement does not include other important aspects of sight like peripheral vision, the ability to see colors or depth perception.

What does visual acuity mean?

Visual acuity is the ability to distinguish details and shapes of objects. Having good visual acuity means that you see things with clarity at a standard distance. It does not include depth perception, peripheral vision, or color blindness.

What tests are used to determine visual acuity?

There are various tests, like the "Random E Test," that can be used to determine the visual acuity of infants, children, and adults. These tests are non-invasive, painless, reliable and can be performed almost anywhere. The results will give your eye health professional information about your sight and what prescription you will need to correct it. Visual acuity tests are fairly simple and can be performed by a technician, nurse, optician, optometrist, or ophthalmologist.

What corrective methods are available?

There are many safe and affordable choices for those who need vision correction. It is important to select a corrective vision method that suits your optical needs and lifestyle.

  • Eyeglasses: Probably the most traditional form of vision correction is the spectacle, or eyeglasses. Glasses work by bending light so it is in focus on the retina. Eyeglasses are practical, affordable, and safe.
  • Contact lenses: Contacts are more suitable for those with an active lifestyle. Contacts work in the same method as eyeglasses, but stay in place better during physical activities. Some people also have cosmetic reasons for using contacts instead of glasses. There are certain refractive errors or eye glass measurements that are better corrected with contacts. Being outdoors means being in the sun, and contacts allow you to wear sunglasses at the same time. There are many different brands, colors, and materials, so it is best to shop around to find the contacts that work best for you.
  • Corrective surgery: Vision correction surgery is performed by changing the refractive, or light-bending, properties of the eye. Refractive surgery is not cosmetic, but rather it is functional because it restores a person’s ability to see at a moderate visual acuity. Some people may not be good candidates for corrective surgery, but the results are usually long-lasting and there is no hassle with daily cleaning or repair.

Why is having good vision so important?

  • Safety: Average activities, such as driving, biking, or even walking can be dangerous for you and others if you can’t see properly. Having good vision can prevent unnecessary mishaps, especially when outdoors or close to traffic.
  • Comfort: Being able to see clearly allows you more freedom in your activities. Having good vision means that you won’t have to squint, whether you’re at the back of the classroom or at the front of the movie theater.
  • Reading ease: Good vision helps you read more comfortably for work, learning, or just enjoyment.
  • Quality of life: With good vision, you will not have to compromise your quality of life by missing out on its most important moments.

Last reviewed by a Cleveland Clinic medical professional on 04/10/2018.

References

  • American Optometric Association. Accessed 4/25/2018. Visual Acuity: What is 20/20 vision? (https://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/visual-acuity)
  • Marsden J, Stevens S, Ebri A. Community Eye Health Journal. 2014;27(85):16. Accessed 4/25/2018.How to measure visual acuity. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4069781/)

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