Changes in ocular structure and visual function with "normal" aging

Gunilla Haegerstrom-Portnoy, O.D., Ph.D. School of Optometry

1. Skin changes (loose, baggy lids) and loss of muscle tone around the eyes leads to ectropion/entropion/senile ptosis/enophthalmos.

2. Tear film changes/ dry eyes common/ tearing.

3. Sclera: fat deposits-yellowing; thinning-"blueing"

3. Corneal diameter does not change after age one.

4. Corneal shape changes with age resulting in a different axis of astigmatism.

5. The average refractive error becomes more hyperopic with age (myopia with incipient cataract).

6. Corneal sensitivity decreases with age (important for contact lens wearers).

7. Transmission of light decreases with age (relatively small effect).

8. Scatter by the cornea increases after 75 years of age.

9. Volume of the anterior chamber decreases with age (caused by growth of lens).

10. Pupil size decreases with age particularly for dim light conditions.

11. The ocular lens grows throughout life.

12. The lens becomes more yellow with age and absorbs more light, significantly changing the amount and quality of light reaching the retina.

13. The yellowing of the lens may accelerate after the age of 60.

14. The amount of lens fluorescence increases with age.

15. Amplitude of accommodation (expressed in diopters) decreases linearly with age (caused by the lens).

16. Presbyopia (loss of accommodative ability) occurs earlier in people who live in warm climates.

17. The vitreous (a gel in youth) becomes liquefied with age making "floaters" more visible.

18. The vitreous commonly detaches from the retina after the age of 60 (same symptoms as retinal detachment).

19. Lipofuscin (aging pigment) accumulates in the retina with age.

20. Photoreceptor density decreases with age; other retinal cell layers become disordered.

22. Visual acuity (ability to resolve detail) declines modestly beyond age 60 when measured with standard high contrast charts. Larger losses are seen for low contrast charts and when testing under conditions of reduced illumination (pupil size, lens changes, retinal changes are causes).

23. The retinal illuminance (the amount of light reaching the back of the eye) for an 80 year old is at least 10 times lower than that of a 25 year old (wearing extra-dark glasses analogy).

24. Visual field size decreases with age (divided attention issue)-neural vs optical cause-recent evidence

25. Color vision changes with age are most commonly of the blue-yellow variety (lens/retina are causes).

26. The ability to adapt to darkness is significantly slowed with age (pupil size/lens/retina are causes).

27. The ability to recover visual sensitivity from bright lights worsens after age 40 (lens/retina are causes).

28. Scatter by the lens causes more glare problems with increasing age.

29. The ability to see rapid flicker worsens with age (note effects of pupil size).

30. Many of the changes in vision function are caused by reduced amount of light reaching the retina.

31. Recommendations:

Wear appropriate optical correction

Increase ambient light level (tungsten light)

Make lighting as even and without glare as possible

Improve contrast in critical areas (ex. tape on stairs)

Avoid large/rapid changes in light level (wear sunglasses outside)

Avoid pastel or muddy colors

Allow more time