There are hundreds of myths and misconceptions about eyesight. Some old wives’ tales have a grain of truth in them: most are myths that need busting.

Here are the facts about some of them:

Myth: Reading in the dark or dim light will damage your eyes

Reading in dim light or in the dark is highly unlikely to cause any permanent damage to your eyes, but it could cause eye strain which can be uncomfortable. Your eyes adjust to the light around them and your pupils enlarge in order to collect the most light.  We are designed to see detail better in the light  so although you will not harm yourself by reading in the dark, it is more difficult to see and may cause a headache.

Myth: Contact lenses can get lost behind your eyes

The membrane that covers the white of your eye (the conjunctiva) also lines your eyelids, so it is impossible for a contact lens to get lost behind your eyes.

Myth: Wearing someone else’s glasses may damage your eyes

Although you may not be able to see very well with them and may get a headache or double vision, you won’t come to any harm from wearing glasses that are not your prescription (unless you’re driving a motor vehicle).

Myth: Watching TV too much or too closely will damage your eyes

Watching too much TV or sitting very close to it may make your eyes tired or give you a headache – particularly if you are watching TV in the dark –  but won’t cause any serious permanent damage.

Myth: Masturbation makes you go blind

The only correlation between the two is that semen contains a large amount of zinc and a deficiency in zinc will cause a decline in a person’s vision. This is virtually impossible to achieve solely by masturbating.

Myth: Exercising the eye muscles can allow you to ‘throw away your glasses’

People normally need glasses because of the shape and size of their eye.  Exercises won’t help this.

Myth: By looking at the patterns, colours and other characteristics of the iris you can tell a person’s health problems

There is no scientific proof for this. However, when optometrists carry out eye examinations they will not only test your sight, but also check the health of your eyes and look for signs of some general health problems.

Myth: Using your eyes too much can wear them out

Your eyes will last for your whole life if they are healthy or have conditions that are treatable. The health of your eyes has nothing to do with the number of hours you use them.

Myth: Holding books up close will damage a child’s eyes

Where or how your child holds a book has no effect on the health of the eyes or the need for glasses. Sometimes children find it more comfortable to read close-up and their very good focusing ability makes it easy for them to do so.

Some truth: Eating carrots will improve your eyesight

Carrots are a source of vitamin A, which is important for the eyes.  However, before you embark on an all-carrot diet to improve your vision, note that it is more important for eye health to have a good balanced diet that supports your all-round health. Poor nutrition has been implicated in diseases such as age-related macular degeneration (AMD).

Some truth: You can sleep in your contact lenses

Unless you have been told specifically by your optometrist that you can sleep in your contact lenses, you should avoid this. Your eyes need to breathe whilst wearing contact lenses, and this is more difficult when your eyes are closed.

This – and the fact that when you are not blinking your contact lenses will not move on your eyes as much as when you are awake – can mean that you are at more risk of infection if you sleep in contact lenses.  Always follow the guidelines given to you by your optometrist. If in doubt, take them out.