Psychophysics of reading - X. Effects of age-related changes in vision

This study examined the influence of age-related changes in vision on reading performance. Maximum reading speed was measured in groups of young (n = 16, mean age 21.6 years) and old (n = 14, mean age 68.3 years) subjects, all with acuities of 20/32 or better. A psychophysical procedure was used for measuring reading speed that has proven reliable and sensitive to visual factors in previous research. Data were collected for character sizes ranging from .15° to 12°. Research revealed that old subjects who were free of eye disease read as fast as the young subjects for character sizes ranging from .3° to 1.0°. This is the range in which reading speed is maximum for young subjects. Research also revealed that old subjects showed a deficit when reading text composed of very small or very large characters. Their speeds dropped to about 70% of the young adult speeds. These deficits may be due to age-related losses in visual contrast sensitivity.