LinkedIn Facebook
 


About 20/20
 

When most of us think of “perfect” vision, we think of 20/20.
We assume that if we have 20/20, our visual system function is normal. If we don’t have 20/20, we need a lens correction to restore our vision to 20/20 – then, our visual system function has been restored to normal. In fact, this is not true.
 

 

And what does 20/20 mean, anyway? Over 100 years ago, a Dr. Snellen determined (by the best scientific methods of the day) the smallest target size a human eye could see. This target size came to be labeled (in the United States) a size 20 letter at a distance 20 feet from the eye. Thus, 20/20 means you can see a size 20 letter at 20 feet away. So, 20/40 means you can see a given letter size at 20 feet at what a person with 20/20 can see at 40 feet. Sound confusing?   It is!!!!!!
 

 

Thus, 20/20 is a measure of visual acuity (clarity) at a 20 foot distance.  Visual acuity is important, but there are other vision skills that can have a significant negative effect if not working properly.
 

 

If a child is struggling in school, make sure  Binocular Vision Function (the ability of the two eyes to team and coordinate together), and the ability to understand or get meaning from the 20/20 visual input is being assessed in  your child's vision evaluation.
 

 



If prescription lenses are required, the lenses will often provide optical correction for:
 

  • Astigmatism – much of the time, light entering the eye horizontally is refracted differently than light entering the eye vertically. Depending upon the amount of Astigmatism, far and near point vision will be blurred. Often, a lens prescription for Astigmatism will also include a correction for Hyperopia or Myopia


  • Myopia (nearsightedness) – the length of the eye is too long, or the optics too strong. Depending upon the amount of Myopia, far point vision is blurred – however, near point vision may be clear or blurred.


  • Hyperopia (farsightedness) – the length of the eye is too short, or the optics too weak. Depending upon the amount of Hyperopia, both far and near point objects are perceived as blurred.
     
 

 

 
If  your child is struggling in school, make sure  Binocular Vision Function (the ability of the two eyes to team and coordinate together), and the ability to understand or get meaning from the 20/20 visual input is being assessed in  your child's vision evaluation.

 

At The Eye Clinic, a Visual Perceptual Assessment or Visual Skills Assessment measures Binocular (both eyes) function, as well as

Visual Motor Guidance ( eye hand coordination), Ocular Motility (eye tracking), Accommodation (eye focusing), Vergence (eye alignment) and Visual Information Processing/Visual Perception abilities are documented. From these findings, treatment options are discussed with each patient and/or family members.

 

Back to Top

 

 

 

 

 

 
© Copyright 2018 The Eye Clinic. All Rights Reserved. Web Design and Content Management by REM Web Solutions.
home about services
vision development
infant vision
preschool vision
school age vision
adult vision
vision dysfunctions
learning, reading & behavioural problems
concussion/brain injury
strabismus & amblyopia
about 20/20
3d viewing
vision therapy
your expectations
attention deficit disorder
dyslexia and reading problems
forms