Your Name (required)

Your Email (required)

Your Message

Type the characters you see below
captcha

0

Night Blindness

Going under the medical name of “nyctalopia” – adapted exactly from the Greek words for night and blindness – this disorder doesn’t allow a sufferer to see anything in the dark, at dusk or in low light.

Night blindness is really a symptom of several other disorders and conditions, some of which are easily treated, and some not:

•    Retinitis Pigmentosa for example is a disorder – the eye, in this case the retina, fails to function correctly.

The retina isn’t a smooth curve at the back of the eye – it’s made up of millions of rods that help to distinguish contrast and see in poor light, and a lesser number of cones that help in seeing colour. When the rods degenerate it’s peripheral vision that suffers first, followed by the ability to see in the dark.

•    Vitamin A deficiency on the other hand is a condition, or a state of health – without vitamins (vital amines) the body just doesn’t work properly.

It’s well known that vitamin C found in oranges helps in maintaining the body’s immune system, and vitamin D from the sun helps the intestines absorb nutrients from food, essentially phosphorus and calcium for bone development. Lack of vitamin D in children has a history of initiating rickets.

Vitamin A is essential in HELPING THE EYES!

Without vitamin A the eyes can be seriously affected by a deficiency directly inducing night blindness.

Things to look out for that happen with night blindness:

Well of course difficulty seeing in dim light is one of the first things, although you should be exempted in the case of a candle-lit restaurant where even people with perfect vision can often struggle!

Others:

•    Not being able to see all the stars and constellations your friends are seeing when you are out on a clear night

•    Having to own up to knocking things over at night because you don’t see them – although you’d like to pretend you just didn’t notice them

•    Having to wait for a while for your eyes to “catch up” when coming into a well lit room from the dark

Treating night blindness

Night blindness as a result of retinitis pigmentosa cannot be treated.

Remembering that night blindness with respect to vitamin A deficiency is related to a condition, or state of health, the treatment is one of increasing vitamin A intake and improvement of general nutrition.

Eat the right foods – typically green vegetables, eggs, milk and tuna

If night blindness is serious then direct injections are an option, but for ongoing health a change in diet would seem to be on the cards!

A word of warning

Unlike vitamin C which is water-soluble and which NOT stored in the body if too much is ingested, vitamin A is fat-soluble and IS STORED IN THE BODY.

Take too much vitamin A and it will be stored in the liver leading to toxicity, logically called “hypervitaminosis A”, the symptoms of which include skin irritation, feeling dizzy and nauseous, and pain in body joints.

The most famous case of vitamin A toxicity concerned Antarctic explorers Mawson and Mertz who after eating liver of their dogs became very ill and Merz did not recover.

But rest assured, it’s extremely unlikely that you would suffer from toxicity eating only vitamin A rich foods – just be wary of too many pills.

About the Author

Dr Jim Kokkinakis (Optometrist) graduated in 1983 from the Optometry School University of NSW. He is currently a Senior Lecturer there and regular speaker to both Optometrists and Ophthalmologists in Australia and Internationally. He has a specialist clinical practice in the Sydney CBD with interests in Eye Strain, Computer Vision problems, Treatment of Eye Diseases and complex Contact lens Fittings.

Leave a Reply




If you want a picture to show with your comment, go get a Gravatar.