NIDEK - Conversion Table for Representation of Visual Acuity

Eye & Health Care

Conversion Table
for Representation of Visual Acuity

Visual Acuity values are represented in decimal, fraction (in feet or meters) and log MAR. Use the table below for conversion between them.

20 ft	6 m	Decimal	4 m	Log MAR
20 / 630	6 / 190	0.032	4 / 125	+1.5
20 / 500	6 / 150	0.04	4 / 100	+1.4
20 / 400	6 / 120	0.05	4 / 80	+1.3
20 / 320	6 / 95	0.06	4 / 63	+1.2
20 / 250	6 / 75	0.08	4 / 50	+1.1
20 / 200	6 / 60	0.1	4 / 40	+1.0
20 / 160	6 / 48	0.125	4 / 32	+0.9
20 / 125	6 / 38	0.16	4 / 25	+0.8
20 / 100	6 / 30	0.2	4 / 20	+0.7
20 / 80	6 / 24	0.25	4 / 16	+0.6
20 / 63	6 / 19	0.32	4 / 12.5	+0.5
20 / 50	6 / 15	0.4	4 / 10	+0.4
20 / 40	6 / 12	0.5	4 / 8	+0.3
20 / 32	6 / 9.5	0.63	4 / 6.3	+0.2
20 / 25	6 / 7.5	0.8	4 / 5	+0.1
20 / 20	6 / 6	1.0	4 / 4	0
20 / 16	6 / 4.8	1.25	4 / 3.2	-0.1
20 / 12.5	6 / 3.8	1.6	4 / 2.5	-0.2
20 / 10	6 / 3	2.0	4 / 2	-0.3