Night Blindness (Nyctalopia): What is it, what causes it and what can you do about it?
10 August 2021
Struggling to see in the dark? It could be night blindness
Night blindness (Nyctalopia) is a condition that inhibits your ability to see clearly at night or in poor lighting, similar to the lighting found in dimly-lit restaurants and cinemas. There are a variety of different causes and treatments for this condition, and the treatment you require depends on identifying what is triggering the condition.
What is night blindness?
Night blindness is a condition that is often associated with an inability to quickly adapt from a well illuminated environment to a poorly illuminated environment. Unfortunately, this can make even the simplest of tasks (like getting up for a glass of water at night) much more difficult than they need to be. Night blindness is also not a disease in itself; rather it’s usually a condition that appears as a symptom of another underlying issue.
The retina at the back of your eye has different types of photoreceptor cells that help you see, and these cells are called rods and cones. Cone cells help you see colour, and rod cells aid your vision in the dark. When the rod cells cannot work properly because of a disease or condition, this can lead to night blindness as your eyes wouldn’t be able to see in low lighting. However, faulty rod cells are not the only possible cause of night blindness.
What is the main cause of night blindness?
Having an eye condition that affects the rod cells in the retina is what usually leads to night blindness. However, this is not the only possible cause, as it also depends on things like your diet or your genetics. Some of the main causes of night blindness are:
- Glaucoma: Glaucoma is a common eye condition that damages the optic nerve, which connects the eye to the brain. When fluid begins to build up in the eye, the eye pressure increases and this could lead to complete vision loss. The medication used to treat glaucoma constricts the pupil, reducing the amount of light going into the eye. This can make those suffering from glaucoma even more susceptible to night blindness. In this case, it’s the pupils that cause the night blindness rather than the photoreceptor cells in the retina.
- Cataracts: A cataract is a clouding of the normally clear lens of your eye. Cataracts can reduce your vision and make everything appear blurry and cloudy. As the clouded lens reduces the amount of light going into the eye, this can make night vision particularly difficult and can lead to night blindness. On the bright side, cataract surgery can easily swap the eye’s clouded lens with an artificial clear one, significantly improving your vision and eradicating your night blindness.
- Myopia: Myopia (or short-sightedness) is the inability to see distant objects clearly, and it’s the most common refractive error among children and young adults. Severe myopia can also contribute to night blindness, as the eye grows too long which prevents the retina from focusing light correctly. Those who are short-sighted often struggle to see anything in the distance, so darkness and poor lighting can understandably make night vision more difficult.
- Vitamin A deficiency: According to the World Health Organization, night blindness is one of the first signs of vitamin A deficiency. Vitamin A is essential for good eye health and for helping your eyes process images, as it transforms nerve impulses into images in the retina. Thankfully, this issue can be easily fixed simply by incorporating more foods that are rich in vitamin A into your diet. Orange coloured foods such as carrots, oranges and sweet potatoes are great examples of this, as well as some other foods like milk, eggs, and spinach.
- Retinitis pigmentosa: Another cause of night blindness is the eye disease, retinitis pigmentosa. This disease triggers the breakdown and loss of retinal cells which can ultimately lead to blindness, as a progressive loss of rods can significantly reduce night vision. Unfortunately, this is a genetic condition with no cure discovered yet. The gene that produces a build-up of pigment in the retina doesn’t respond to surgery or corrective lenses.
How do you know if you have night blindness?
Struggling to see in the dark and dim lighting is something we all struggle with sometimes, but it might not always be a sign of night blindness. Some of the symptoms of night blindness include:
- Blurry vision
- Difficulty spotting obstacles in dim lighting
- Struggling to adjust to brightness quickly
- Headaches
- Eye pain
- Nausea
- Vomiting
- Difficulty seeing into the distance
- Light sensitivity
Can night blindness be cured?
Sadly, night blindness isn’t always treatable, depending on the underlying issue that is causing it. If your night blindness is a result of vitamin A deficiency, that can be easily rectified by changing your diet. Similarly, undergoing eye surgery for glaucoma or cataracts can also alleviate any symptoms of night blindness. However (as mentioned above), retinitis pigmentosa currently has no cure, and as it’s a genetic connection it can’t be treated through any other method.
You may not be able to prevent night blindness as a result of a genetic condition, but you can eat a healthy, balanced diet that would make night blindness less probable. Eating foods that are rich in vitamin A, antioxidants and minerals will significantly reduce your risk of night blindness. If you think you may be suffering from night blindness, take necessary precautions and avoid driving at night as much as possible until your night blindness can potentially be treated.
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