There is no single "perfect" eyesight number. While 20/20 (or 6/6 in metric) is often cited as perfect vision, it's actually considered average or normal visual acuity. Many individuals, particularly children, possess visual acuity better than 20/20, with some achieving 20/15 or even better.
Understanding Visual Acuity Numbers
Visual acuity is measured using a standardized eye chart (like the Snellen chart). The numbers represent a ratio:
- The first number (20 or 6): This represents the distance in feet (20) or meters (6) at which the test is conducted.
- The second number (20, 15, 10, etc.): This indicates the distance at which a person with average vision can read the same line.
Therefore:
- 20/20 vision: Means you see at 20 feet what a person with average vision sees at 20 feet.
- 20/15 vision: Means you see at 20 feet what a person with average vision sees at 15 feet (sharper than average).
- 20/40 vision: Means you see at 20 feet what a person with average vision sees at 40 feet (less sharp than average).
Several sources confirm that 20/20 vision is not the pinnacle of visual acuity. Better-than-average vision is achievable, and the term "perfect" is subjective and not clinically defined in terms of a specific numerical value.
For example, the American Academy of Ophthalmology states that 20/20 vision is not perfect vision and that 20/15 vision exists, representing sharper than average vision. https://www.aao.org/eye-health/tips-prevention/what-does-20-20-vision-mean Similarly, the Optometric Education website notes that 20/10 vision is achievable, meaning one can see at 20 feet what the average person sees at 10 feet. https://optometriceducation.org/2020/01/02/can-you-have-better-than-20-20-vision/
