It’s easy to see that, as you age, you may not be getting or absorbing enough nutrients from your diet. When you combine this with the fact that certain muscles in the eyes weaken with age, before you know it, your vision has decreased noticeably — particularly your night vision. Medical experts report that a 50-year-old driver needs twice as much light to see after dark as a 30-year-old.
What changes are taking place in your eyes as you age?
In dim light, your eyes adapt by widening the pupils. This lets in as much light as possible. The colored part of your eye that surrounds the pupil, called the “iris,” has tiny muscles. These muscles control the size of the pupil. As you age, these muscles weaken and don’t react as well when you are in a dark environment. Your pupils stay small and you have less light to see with.
Night blindness happens when your eyes can’t adjust to changes in light intensity. For example, you may find that your eyes cannot adjust to dim indoor light after being outside under natural sunlight. Of course, night blindness is often much more serious than this relatively mild example.
Night blindness is often regarded as a vitamin-A-deficiency disease. Vitamin A helps form a light-sensitive pigment that receives and sends images to the brain.
In one clinical trial, researchers wanted to review the effects of supplementation of vitamin A during pregnancy, alone or in combination with other vitamins and micronutrients. The team collected data on 16 clinical trials.
They found that vitamin A supplementation reduced the risk of maternal night blindness. On an interesting side note, they also found that, in HIV-positive women, vitamin A supplementation given with other micronutrients was associated with fewer low-birth-weight babies.
The researchers concluded that vitamin A supplementation reduces the risk of night blindness and may help in a reduction of infection in maternal women.
The RDI for vitamin A is 750 micrograms/day.
Here is a list of vitamin-A-rich foods:
- Sweet potatoes
- Winter squash
Zinc is another important key to reducing or preventing night blindness. Zinc helps increase the activity of an important enzyme in your eye that is needed by vitamin A. So zinc and vitamin A work together.
You can get a healthy dose of zinc by adding these foods to your diet:
- Red meat and poultry
- Whole grains
- Fortified cereal
- Dairy products