TRADITIONAL SNELLEN EYE CHART REVERSE WITH RED GREEN BARS, VISUAL ACUITY TEST 6M / 20FT

The Snellen eye chart was originally introduced in 1862 by Herman Snellen. The Snellen eye test uses the idea of a subtended 5 minutes of arc with a 20-foot distance. This became the “standard vision” measurement. Also, Snellen developed the idea of a 5×5 grid for a standard for his optotypes. Each optotype must meet certain percentage requirements in this grid before it is used for testing. This helps to make a uniform and equal vision chart. The Snellen eye chart is the basis for many other vision tests.

Features

• Chart includes red and green color bars for an easy and helpful color vision test.
• Made of Extra Strong, Easily Washable, Non-reflecting, Matte Finish PVC Sheet.
• Perfect for optometrists, students, offices, and schools. • And the top centre
• hole, easy to hang on the wall.
• Eye chart measures 28 X 56 cm (11 X 22 in.)