Geriatric Medicine

Answer 2 Yellowing of the cornea and lens. Yellowing of the cornea and lens causes an elderly person to see through a yellow filter. Not only does this reduce the amount of light reaching the retina, but it also causes a frequency shift of that light. The result is impaired color discrimination under conditions of low ambient light. Glaucoma has no effect on color perception in a low-light environment. Macular degeneration can lead to impaired visual acuity, but it should not have a significant effect on color vision. Memory loss severe enough to impair a person’s ability to drive is a pathologic—not physiologic—change, because it is severe enough to interfere with occupational functioning.1 Stiffening of the lens affects only focus and accommodation; it has no effect on color perception. REFERENCE 1. Diagnostic and statistical manual of mental disorders: DSM-IV-TR. 4th ed, text revision. Washington (DC): American Psychiatric Association; 2000:148-9. Click here to return to the questions

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