© 2022 HealthNews - Latest tech news,
product reviews, and analyses.

How to Overcome Issues When Driving in the Dark


If you have problems driving at night, it could be related to the eye’s natural aging process. However, diminishing night vision can also indicate an eye condition that requires treatment.

As humans, our eyes are not well-adapted to see at night, compared with animals like cats and owls. Human eyes have fewer rods, which are photoreceptors in your retina (light-sensitive tissue in the back of the eye) that detect light and help you see in dim light. Conversely, we have better color vision than other creatures due to our retina’s higher concentration of cone photoreceptors.

Approximately 30% of rods are lost by 70 years of age, which means your night vision reduces over time. However, there are other factors that also influence how well you see in the dark.

Eye conditions that affect night vision

If you have more difficulty than other people seeing at night, you have nyctalopia (night blindness). Nyctalopia isn’t a disease but a sign of an underlying problem. Here are some conditions that affect night vision and how to treat them.

Myopia (nearsightedness) and astigmatism

Myopia and astigmatism occur when the shape of your eye prevents images from focusing properly on the retina. These vision conditions cause you to see things at a distance as blurry, especially at night when myopia is more pronounced (night myopia). Astigmatism also induces glare, such as from oncoming headlights.

These conditions are quite common. Studies estimate that by 2050, nearly 50% of the world’s population will have myopia.

The best solution is to have your eye doctor prescribe glasses or contact lenses to correct myopia and astigmatism. In addition, you can add anti-glare coating to your glasses to further improve the quality of vision and reduce glare.

Cataracts

Cataracts are a common condition in older age. They form when the lens inside your eye becomes cloudy from age, sun exposure, trauma, diabetes, certain medications, or other reasons. Cataracts prevent adequate light from entering your eye and can cause blurry vision, halos, and glare.

Surgery to remove the cataract provides a permanent solution. The surgeon also places an artificial lens into your eye to restore vision.

Constricted pupils

During the day, your pupils are smaller to control the amount of light entering. In dim light, your pupils expand to allow more light in. However, there are some reasons why your pupil may be constricted (miosis) and unable to adjust in the dark:

  • Medications including opioids, antipsychotics, and pilocarpine eye drops
  • Drugs like heroin and PCP
  • Insecticides
  • Tobacco products
  • Cluster headaches are severe headaches on one side of the head or around the eye
  • Horner’s syndrome, which affects the sympathetic nerves of your eyes and face
  • Lyme disease is a bacterial disease transmitted by deer ticks
  • Multiple sclerosis is a disease of the brain and spinal cord
  • Neurosyphilis occurs when untreated syphilis affects the brain
  • Brain hemorrhage is a life-threatening stroke that occurs when an artery in the brain bursts

Treatment depends on the underlying cause, including discontinuing the medication causing miosis. However, a stroke requires emergency medical attention.

Vitamin A deficiency

If your diet doesn’t provide adequate amounts of vitamin A, you can develop nyctalopia. Your body needs vitamin A to produce rhodopsin, a pigment in rod photoreceptors.

Some excellent sources of vitamin A are:

  • Leafy greens like kale and spinach
  • Sweet potato
  • Pumpkin
  • Tomatoes
  • Carrots
  • Red bell pepper
  • Mango
  • Herring fish
  • Beef liver
  • Eggs
  • Milk

Vitamin A deficiency can also cause dry eyes, infections, clouding of the cornea (clear front of the eye), keratinization (toughening of tissues in the body), skin problems, and other health issues.

Retinitis pigmentosa

Retinitis pigmentosa (RP) is a group of genetic conditions that cause progressive loss of rod and cone photoreceptors (mostly rods), resulting in loss of peripheral vision and nyctalopia. RP affects one in every 5000 people worldwide. In advanced stages, RP causes poor daytime vision or even blindness.

RP is associated with various genetic mutations, such as in gene RPE65. Luxturna, a form of gene therapy, injects a copy of healthy RPE65 into the retina. This treatment can help improve night vision in less advanced cases of RP. More treatments are on the horizon, including other gene therapies.

Conclusion

A decreased ability to see at night isn’t always cause for concern and may simply be related to age. While some causes for poor night vision are easily fixed, others are more complex and require prompt medical attention. If you are concerned about your ability to drive at night, consult your eye doctor for a diagnosis and solutions.

Key takeaways

Myopia and astigmatism are common vision problems that affect night vision. They’re primarily corrected with glasses and contacts.

Cataracts are a normal part of aging but can be exacerbated by other factors. If they impair vision, they can be removed surgically.

Our pupils function to control light entering the eye, depending on our environment. Constricted pupils could indicate severe health conditions that require immediate medical attention, such as a life-threatening stroke.

Vitamin A deficiency causes poor night vision, along with other health problems. Fortunately, there are a variety of vegetables, fruits, dairy, fish, and meats that are rich in vitamin A.

Resources:

American Academy of Ophthalmology. New Treatments for Retinitis Pigmentosa.

Cleveland Clinic. Eye Miosis.

Cunea, A., et al. (2014). Death by color: differential cone loss in the aging mouse retina. Neurobiology of Aging.

Holden, B.A., Fricke, T.R., Wilson, D.A, et. al. (2016). Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology.

Mehra, D., Le, P.H. (2021). Physiology, Night Vision. StatPearls.

National Institutes of Health. Vitamin A and Carotenoids.

O’Neal, T.B., Luther, E.E. (2021). Retinitis Pigmentosa. StatPearls.

Leave a Reply

Your email address will not be published. Required fields are marked