The Single Symbol Book is designed for testing children and adults who
have difficulties in perception of symbols in lines. The visual acuity
values measured with single symbols are often several lines better than
the line acuity values in persons with impaired vision and thus
overestimate the quality of visual functioning. Single optotype line
sizes from 20/200 to 20/8 (6/60 to 6/2.4) equivalent, 0.10 to 2.50.
Includes isolating mask, response key, training cards, and instructions.
13 offset pages for easy flipping. 5" x 5" (12.7 cm x 12.7 cm).