During a routine eye exam, you'll be asked to read letters and numbers on a chart. The purpose is for an optometrist to determine your visual acuity, which measures the sharpness of your vision when focusing on objects from different distances. In popular culture, the measurement of 20/20 is famous for representing excellent vision. Here's a closer look at how accurate its reputation is.

How Is 20/20 Vision Measured?

The Snellen system measures the acuity of central vision during an eye exam. With one eye covered at a time, you read aloud a series of letters on a chart located on the opposite wall from where you are seated. As you move down the chart, the letters gradually become smaller.

The standard testing distance is 20 feet and serves as the top number in a visual acuity measurement. Ideally, when eye muscles are relaxed, a person should be able to focus on objects that are 20 feet away or farther. The muscle tightness changes to focus on objects that are closer than 20 feet away. The bottom number of the Snellen scale refers to the distance in feet someone with normal eyesight requires to accurately read the same line.      

Is 20/20 an Indication of Perfect Vision?

A person with a 20/20 visual acuity measurement has normal vision. This means that from 20 feet away, they can read letters on the chart that most people with healthy vision can also read from the same distance. An optometrist generally prescribes eyeglasses or contact lenses or recommends laser eye surgery to help a patient achieve 20/20 vision. 

When the bottom number is less than 20, it means a person's vision is better than normal. This would be the case, for instance, if their visual acuity measurement is 20/10. When the bottom number is greater than 20, it means their vision is below normal. Therefore, when someone uses a cliche like "Hindsight's 20/20," they're not referring to particularly sharp vision.

For an eye exam to determine your visual acuity and the next steps to take, reach out to Russellville Eye Clinic PA. The Pope County, AR, practice specializes in ophthalmology services. An optometrist will perform the initial eye exam, while an ophthalmologist will provide eye surgery or additional treatments to correct your vision problems. Learn more about their available services online, and call (479) 968-7302 for an appointment.