The preliminary results shown after the test represent the measurement of your visual acuity. Visual acuity refers to the sharpness of your vision. That means the ability to recognize signs on a standardized chart from a specific distance.
There are several systems to express the measured visual acuity, for example the “20/20”-system or a percentage system.
“20/20-vision” is widely used especially in the US and means that you can see clearly at 20 feet what the average person sees at that distance. If the second number is higher than 20, it means your vision is below average and if it’s smaller than 20, your vision is above average. As an example, a person with 20/40-vision sees at 20 feet, what an average person can see at 40 feet away. A person with 20/10-vision, however, can see objects clearly at 20 feet, while the average person needs to stand closer, at 10 feet, to see it.
Percentage: The visual acuity can also be expressed in decimals or percentage for example 80% (0.8), 100% (1.0), or 120% (1.2). In this system, 100% or 1.0 means the average vision, 200% or 2.0 is the highest possible value and indicates very sharp, way above-average vision.
Unaided visual acuity is measured without any glasses or contact lenses on and aided visual acuity is measured with glasses or lenses on. The measured vision that matters, for example for getting a driver’s license or to determine if someone has poor vision, is aided visual acuity.
Visual acuity is a great standardized way to see how well one can see, but does not include the values you need to buy glasses or lenses such as Strength, Cylinder and Axis. This requires a prescription of glasses or lenses, which can easily be validated for you by the experienced optometrists at easee. On your validated prescription you will find the strength of your cylinder, in case you have one, and its direction. With these details you will be able to buy new glasses or lenses. If you order the validated prescription, you’ll receive your values within 24 hours in your account environment.
Furthermore, visual acuity does not tell you everything about the functioning of the eye. Other methods to test the visual function are, for example, contrast sensitivity test, field of vision test and colour test charts.