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 persons ability to drive is a pathologicnot physiologicchange, 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.
- Yellowing of the cornea and lens.
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
Seminars in Medical Practice
Hospital Physician Board Review Manuals
Copyright © 2009, Turner White Communications
Updated 1/04/08 kkj