What is Visual Acuity?
Visual acuity is a term used to describe the clarity/sharpness of vision. An common example is “20/20 Vision”. Visual acuity is measured at a distance of 20 feet. Stating that you have 20/20 vision means that you can see clearly at 20 feet what should normally be seen at 20 feet. Stating that you have 20/50 vision means that you can see clearly at 20 feet what a normal vision could see at 50 feet.
Is 20/20 Vision “Perfect” Vision?
The number assigned to visual acuity measurements is only one part of vision. Other aspects of vision that should be considered are peripheral vision, eye coordination, depth perception, color vision and focusing ability. A person with 20/20 vision may have a problem in one or more of these other areas and have visual complaints.
Visual Acuity Q&A
What does 20/20 vision mean?
20/20 vision is an indication of visual acuity measured at 20 feet. 20 feet is used as the standard measurement by doctors in the United States. A person with 20/20 vision can see clearly at 20 feet what should normally be seen clearly at that distance.
Is 20/20 vision “perfect” vision?
No. 20/20 is only a standard measurement used to describe someone who is seeing well at 20 feet. Other important areas of vision include color vision, depth perception, focusing ability, peripheral vision and eye coordination. A person may have 20/20 vision and have problems in one or more of these other areas diminishing their visual experience.
Does visual acuity change depending on the distance of the object you’re looking at?
Yes. Some people can see very well at a distance, but are unable to see object clearly up close. For others, near objects may be clear and distance vision is blurry.
Why do some people have vision that is worse than 20/20?
Many factors can affect a person’s visual acuity. These factors include being nearsighted or farsighted, having astigmatism or having a number of eye diseases that decrease visual performance.