What does bested visual acuity mean?
Best-corrected visual acuity refers to the measurement of the best vision correction that can be achieved using glasses or contact lenses.
What is the eye vision scale?
Snellen charts display letters of progressively smaller size. “Normal” vision is 20/20. This means that the test subject sees the same line of letters at 20 feet that person with normal vision sees at 20 feet. 20/40 vision means that the test subject sees at 20 feet what a person with normal vision sees at 40 feet.
What is the normal visual acuity?
20/20 vision is normal vision acuity (the clarity or sharpness of vision) measured at a distance of 20 feet. If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at a distance.
How do you test Bcva?
The Snellen chart test and the ETDRS chart test are the current standard methods for testing BCVA in clinical and research settings,4 and Pelli–Robson charts are one of the most common methods for testing contrast sensitivity.
What is 6 12 line on the eye chart?
If this is the smallest line a person can read, the person’s acuity is “6/12” (“20/40”), meaning that this person needs to approach to a distance of 6 metres (20 ft) to read letters that a person with normal acuity could read at 12 metres (39 ft).
What do the numbers 20 50 mean for visual acuity?
The study defines “visual impairment” as visual acuity of 20/50 or worse in the better-seeing eye. Visual acuity refers to the sharpness of vision at 20 feet from an object. A person with 20/50 vision can clearly see something 20 feet away that a person with normal vision can see clearly from a distance of 50 feet.
What is a BCVA score?
Visual function of the study eye was assessed at a distance of 4 meters at every study visit using the Early Treatment Diabetic Retinopathy Study (ETDRS) Best Corrected Visual Acuity (BCVA) letter score. A higher score represents better vision. A higher score represents better vision.