Purpose
The purpose of this study was to determine the effect of luminance on the performance on a new near vision, number reading chart designed to measure visual efficiency, the Odom-Robin Visual Efficiency Chart.
Methods
81 students whose mean age was 12.61 years (range 9-15 years; SD=1.2 years) who were participating in an After School All Stars Reading Camp at St. John’s University were tested using the first three panels of the Odom Robin Visual Efficiency Chart under two lighting conditions, using room lighting of 20 ft-candles and a Spring Light with an illuminance of 100 ft-candles. The two lighting conditions both had color temperatures of approximately 2700K. The Odom-Robin Chart is a near vision number reading chart which consists of numbers which must be read and compared as same and different. The chart consists of 10 blocks of numbers whose sizes range from 0.9 LogMAR to 0 LogMAR in 0.1 LogMAR steps. Five lines and two columns of the same print size are grouped into a block. Students read each line of the three largest sizes (15 lines), indicating whether the two numbers on each line were the same or different. Test distance was 40 cm. The time required to read the 15 lines with no more than one error per block of 5 lines was recorded. Students were tested twice on the same day, one light in the morning and the other in the afternoon. The sequence of lighting conditions was varied so that half of the students received one light first and the other half the other light first.
Results
Students completed the test in 76.5±26.0 sec on average in the room lighting condition and 80.95±36.0 sec using the Spring Light. The mean difference -4.4±21.6 sec was not statistically significant (p = 0.0687). Performance on the Odom-Robin chart correlated significantly across the two lighting conditions (r = 0.81, p < 0.0007). The slope of the linear regression relating the two values, 1.18, was not different from 1 (p > 0.10).
Conclusions
Consistent with visual acuity research and data from other vision charts, performance on the Odom Robin Chart is relatively insensitive to changes in illumination within the photopic range. Scores obtained with classroom lighting and with special lighting will be comparable.
Keywords: 465 clinical (human) or epidemiologic studies: systems/equipment/techniques •
754 visual acuity •
709 screening for ambylopia and strabismus