ETDRS Original Series Chart R Sku(s): 500013 (Standard), 511113 (Roll-up) Description: ETDRS eye chart - Original series chart R with proportionally spaced (geometric progression) lines; line sizes range from 20/200 to 20/10 (6/60 to 6/3) equivalent. Standardized format used in National Eye Institute clinical studies and in low vision evaluations that require accurate and repeatable visual acuity measurements. Chart measures 24.5" x 25.5" (62 cm x 65 cm). Available in 2 different versions: The Standard ETDRS style chart is screen printed on .010 thick styrene plastic making the chart more rigid. The Roll-Up ETDRS style chart is screen printed on .015 thick styrene plastic allowing the chart to be rolled up for easy transporting or storage. Both are UV coated for long lasting durability. 13 feet, 4 meter testing distance.