A visual acuity test is an eye exam that checks how well you see the details of a letter or symbol from a specific distance. Visual acuity refers to your ability to discern the shapes and details of the things you see.
A visual acuity test is an eye exam that checks how well you see the details of a letter or symbol from a specific distance. Visual acuity refers to your ability to discern the shapes and details of the things you see. It’s just one factor in your overall vision. Others include colour vision, peripheral vision, and depth perception.
There are several different types of visual acuity tests, most of which are very simple. Depending on the type of test and where it’s conducted.
· Snellen – The Snellen test uses a chart of letters or symbols. You’ve probably seen the chart in a school nurse’s office or eye doctor’s office. The letters are different sizes and arranged in rows and columns. Viewed from 14 to 20 feet away, this chart helps determine how well you can see letters and shapes.
A common cause of low visual acuity is refractive error (ametropia), or errors in how the light is refracted in the eyeball. Causes of refractive errors include aberrations in the shape of the eyeball or the cornea, and reduced flexibility of the lens. Too high or too low refractive error (in relation to the length of the eyeball).
How to Identify?
Clarity of vision. Visual acuity is dependent on optical and neural factors, i.e., the sharpness of the retinal focus within the eye, the health and functioning of the retina, and the sensitivity of the interpretative faculty of the brain.
Visual acuity is expressed as a fraction, such as 20/20. Having 20/20 vision means that your visual acuity at 20 feet away from an object is normal. If you have 20/40 vision, for example, that means you need to be 20 feet away to see an object that people can normally see from 40 feet away. If your visual acuity is not 20/20, you may need corrective eyeglasses, contact lenses, or surgery. You might also have an eye condition, such as an eye infection or injury that needs to be treated.
What to Do?
You may need an eye exam if you feel you’re experiencing a vision problem or your vision has changed. A visual acuity test is one part of a comprehensive eye exam. Children frequently take visual acuity tests. Early testing and detection of vision problems can prevent issues from getting worse. Optometrists, driver’s license bureaus, and many other organizations use this test to check your ability to see.