Watching TV can reveal many eyesight problems - here are a few that could affect you while you are sitting in front of your favourite program.

How do refractive errors cause blurred vision?

If you find it hard to focus on the TV, it could be the result of a refractive error preventing you from seeing clearly. If you are having trouble with your close up vision you may have long-sightedness. This will make it harder to focus when looking at a computer. Objects may become blurry and hard to see. As people get older they often develop an age-related form of this known as presbyopia.

On the other hand, if you are struggling to see items in the distance, you may suffer from short-sightedness. This will be obvious if you are trying to watch TV from a distance. Short-sightedness, or myopia, usually reveals itself in childhood or adolescence. Blurry vision could also be the result of astigmatism, which can cause trouble at any distance as it means objects cannot be focussed properly on your retina - the light sensitive layer at the back of the eye. All of these issues can be corrected using glasses, contact lenses or by surgery. However, you will need to have an eye test at the optometrist to determine whether this is the cause of your blurry vision.

Why do I have double vision when looking at the computer?

Double vision, or diplopia, can be caused by a variety of issues. However, if it only affects you when you are watching TV or watching your favourite shows on a computer, it may be the result of eye strain. This is when your eyes work really hard on one task. It simply means that your eyes have become tired. While no damage will result, it is important to take regular breaks and make sure you are blinking often. Eye strain can also cause sore eyes and headaches. If regular breaks do not relieve your symptoms, you should make an appointment with your optometrist for a check up to ensure there is nothing else going on. Some people find that eye strain is worse at night time. This could be because you are more tired, or it could be a combination of eye fatigue and a refractive error. Corrective lenses should help to relieve this problem.

Why do the colours on TV look different between eyes with macular degeneration?

Macular degeneration often leads to colour vision changes and this is normal with the progression of the disease. Macular degeneration occurs when the macula, or part of the retina responsible for sharp, central vision, begins to decline. This is essential for tasks such as reading and writing. As a result of the disease, central vision loss may occur. It can be diagnosed as a dry or wet degeneration. Wet means there is growth of new blood vessels in an area where they are not meant to be. There is no cure for dry macular degeneration but it can change to become wet in time. There are some forms of treatment available for wet degeneration. Consult your optometrist to find out what could be suitable for you. You may want to visit your optometrist if you are concerned about your retinas and they can refer you to an eye specialist if required.

Why does my child tilt his or her head when watching TV?

If you have a young child, they may tilt their head to correct a vertical imbalance between their two eyes to avoid double vision. However, if there is no muscle imbalance and the head tilting only occurs in front of the TV, it could just be an odd habit. Make an appointment with your optometrist if you are unsure about this.