Sight Line, a critical line flipbook used at a 10-foot (3 meters) screening distance, includes NCCVEH-optotypes: LEA SYMBOLS®. Each card contains five LEA SYMBOLS® optotypes surrounded by a 50%-spaced crowding box.
This critical line test of visual acuity includes:
- 2 lines of 20/50 for children ages 3 years for screening each eye monocularly.
- 2 lines of 20/40 for children ages 4 and 5 years for screening each eye monocularly.
- 2 lines of 20/32 for children ages 6 years and older for screening each eye monocularly.