Seeing into old age: Vision function beyond acuity

Purpose, To provide a comprehensive description of vision function beyond a cuity in older individuals. Methods. A sample of 900 individuals between th e ages of 58 and 102 years (mean age of 75.5) was binocularly tested wearin g habitual correction on a battery of psychophysical tests including high a nd low contrast acuity, low contrast low luminance acuity, disability glare , contrast sensitivity, color vision, stereoacuity, recovery from glare, an d attentional visual fields. Results. High contrast acuity is reasonably we ll maintained on average, even into very old ages. Spatial vision measures under conditions of reduced contrast or luminance, or glare reveal signific ant impairment in a large portion of the aged. Many older individuals also have greatly reduced stereopsis, poor color discrimination, and severely re stricted peripheral fields under conditions of divided attention. A single exponential function relating performance to age fits all spatial vision da ta sets. The function for individual spatial measures lies at different pos itions along the age scale. The derived aging function with a time constant of similar to 15 years also fits results from other recent aging studies o f acuity and contrast sensitivity, Conclusions. Standard visual acuity unde restimates the degree of vision function loss suffered by many older indivi duals under the nonoptimal viewing conditions encountered in daily life. Al l spatial vision functions show a similar rate of decline with age of the p opulation, but the age at which decline begins varies among measures.