January 24, 2018

Caregiving for the Aging Senses Part 1: Vision

It is no secret that eyesight tends to deteriorate with age. The age-old trope of a grandma with thick-lensed glasses is so ingrained in society that we practically expect our elders to have poor vision.

For people who have had good vision for most of their lives, losing the ability to rely on sight for interaction with the world can be extremely disorienting.

By understanding why and how the eye ages, caregivers can make small environmental adjustments that drastically improve the lives of their loved ones.

Loss of Focus

Simulation: 30 years vs. 80 years

As the lens of the eye ages, it loses elasticity and begins to harden.  In a young eye, the lens will bend when viewing something up-close, thus bringing the object into focus.

As it becomes stiffer, the lens can no longer bend sufficiently to focus on objects that are too close. This condition, called presbyopia, makes it difficult to read and can cause persistent headaches.

How to help:

  • Most aging people will eventually require reading glasses, bifocals or contacts. However, because the condition of eyes can change rapidly, make sure your loved one has regular eye exams to monitor the progression of their presbyopia. They may need to get new prescriptions every one to two years.
  • Provide bright, even lighting for reading or other activities that require up-close focus, such as knitting. Using light that is too concentrated (a single bright bulb) can cause glare.
  • Make sure your loved one has glasses or other corrective lenses specific to their daily activities. For example, playing the piano or using the computer might require a different lens than reading, as/because the object of focus is slightly farther away.

Darker Vision

Simulation: 30 years vs. 80 years

Aging pupils are decreasingly sensitive to changes in light, in addition to becoming smaller. Because older eyes cannot respond quickly to changes in light levels, turning a light on or off suddenly may impair vision for several minutes. Smaller pupils also absorb less light, meaning that an older person has a darker field of vision overall.

How to help:

  • Provide adequate lighting for your loved one’s entire living environment. The light may be brighter than you think is necessary, but remember that your loved one’s vision may be 10-40 percent darker than your own.
  • Keep bright (possibly even motion-activated) nightlights in bedrooms, hallways, bathrooms and any other areas that your loved one uses at night.
  • Be particularly attentive to your loved one when you are out with them at night, or even a dark place such as a movie theater. Keep in mind that they might not be able to see obstacles, changes in their walking surfaces, stairs or even other people.

Yellowing of Vision

Simulation: 30 years vs. 80 years

With age, and the resulting lifelong exposure to irritants, the lens of the eye gradually yellows. This can cause several distressing problems for your loved one, including trouble differentiating colors, dulling of color, and even changes in their circadian rhythm.

Blue light (think of bright daylight) triggers our body’s production of serotonin (a chemical that wakes us up), while yellow light (such as the soft lighting in your home) triggers the production of melatonin (a chemical that helps us sleep). Thus, as the eye’s lens yellows, it absorbs less blue light. The resulting drop in the body’s production of serotonin can adversely affect the circadian rhythm, and consequently, interrupt healthy sleep patterns.

How to help:

  • Install fluorescent or LED lighting, both of which emit blue light. By increasing the amount of blue light in your loved one’s environment, you can counteract some of the yellowing of their lens so that they see colors more accurately. This can also help restore normal circadian rhythm.
  • Assist your loved one with color-sensitive tasks, such as picking out an outfit.

If necessary, consult with a sleep specialist, who may be able to improve the quality of your loved one’s sleep.

For more information on age-related vision problems and how to help compensate, visit: http://www.visionaware.org/info/for-seniors/1

References:
https://www.aoa.org/patients-and-public/good-vision-throughout-life/adult-vision-19-to-40-years-of-age/adult-vision-41-to-60-years-of-age
https://nei.nih.gov/healthyeyes/aging_eye
http://www.visionaware.org/info/your-eye-condition/eye-health/normal-vision-changes/125