Product Number : 256100
 
These five LEA SYMBOLS® Cards can be used for presentation as single optotypes or arranged in a row as a line test. When the cards are next to each other, the space between the symbols is equal to the width of the symbols. To determine the visual acuity, use the following formula:
 
VA = Viewing Distance Used(meters) / M-value
 
Dimensions: 60M cards - 8.6" x 8.6" (21.9 cm x 21.9 cm). 40M cards - 6" x 6" (15.25 cm x 15.25 cm).