Beyond 20/20: Understanding Visual Acuity and Eye Charts

From the moment we wake up until we go to bed, our vision plays a pivotal role in shaping our experiences. But how do we ensure that our eyes are functioning optimally? Your eye exam at Premier Eye care & Surgery Center, or any ophthalmologist, will consist of various visual assessments as well as advanced technology to measure and diagnose your visual acuity and any underlying eye conditions. Most eye exams will begin with an indispensable yet humble tool-the eye chart. Let’s delve into what this means beyond 20/20 and how understanding visual acuity and eye charts is not only proactive in assessing your eye health but ensuring your best vision possible. 

While you may be familiar with the standard Snellen eye chart with letters, numbers or symbols that become increasingly smaller in font size as you make your way down the list, you may not be entirely sure of the insights your doctor is gaining through asking you to read off the information. The Snellen chart remains the most wide-spread clinical practice for measuring monocular and binocular visual acuity, the measure of the ability of the eye to distinguish shapes and the details of objects at a given distance. These characters are carefully selected to ensure uniform legibility and are arranged in an equalized format. Eye charts have multiple rows of characters, with each row corresponding to a specific visual acuity level. The characters decrease in size from the top row to the bottom, challenging the viewer’s ability to discern smaller details. Eye charts are designed to be viewed from a specific distance, typically 20 feet away. The test results are then standardized based on this distance, allowing for accurate comparisons. The measurement is expressed as a fraction, with the numerator representing the testing distance and the denominator indicating the distance at which a person with normal vision could read the same line. This is where the normal range designation of 20/20 makes a bit more sense. This information is vital for determining refractive errors and prescribing eyeglasses or contact lenses to improve clarity.

While modern advances do wonders for improving vision, both doctors and patients understand visual acuity and eye charts go hand in hand. This simple yet effective method of testing provides early detection of issues, the ability to monitor changes over time, assessing how well the eyes work in tandem, screening of eye diseases, customization for vision correction and promoting overall eye health. 
For these benefits and more, schedule your next appointment with Premier Eye care & Surgery Center by calling 847-459-6060 or submitting a request at WEBSITE.