Understanding Myopia / Short sightedness

Myopia, commonly known as short-sightedness is a very common condition where patients can see objects near to you but objects farther away are blurry.

Trends of Myopia

In 2050, a total of 4758 million people worldwide , which is almost 50% of the world’s population, are expected to be myopic.

In Singapore, myopia is one of the biggest public health challenge. Surveys done locally indicated that myopia affects one in four 7 year olds, 1/3 of 9 year olds and half of 12 year olds. By 2050, its projected that 80-90% of all Singapore adults above 18 will be myopic.

How Myopia develops

Eye Structure

• The cornea - is the clear dome shaped front surface of your eye where light enters The eye.
• The lens - is a clear structure about the size of an M&M candy that focuses the light that enters our eye.
• The retina - The retina is found at the back of your eye to receive the light rays from objects.

Think of the retina like the white screen, the lens like that small knob where u can turn to sharpen your image and the cornea as the hole where light is emitted.

What happens to a myopic eye

Myopia occurs when eyeball is longer than normal, or if the lens and cornea is not evenly and smoothly curved or in some cases a combination of both.

This will result in the image being focused in front of the retina instead of directly on the retina.

Causes of Childhood Myopia

Evidence suggests that childhood myopia or short-sightedness is caused by a combination of genetic factors and environmental factors. We know that children of myopic parents are more likely to have myopia.

But what are some of the other environmental factors that can result in increased risk of myopia?

They include : 

• Prolonged periods of detailed or close work such as reading and writing or computer and tablet usage
• Lack of time spent outdoors

Signs of myopia

• You may find them squinting all the time when looking at distance objects or images
• You realise that they are sitting closer and closer to the TV or moving to the front of the classroom to get a better view
• Blinking excessively
• Rubbing his or her eyes frequently
• Seemingly unaware of distant objects

Slow down progression of Myopia

Myopia cannot be reversed or cured, but it can be prevented or slowed down. It is important to delay and slow down the onset and progression of myopia because children with high or severe myopia have higher risks of complications in future like retinal detachment, glaucoma, macular degeneration and even blindness.

Practise good eye care habits

• While near works such as school work, working on computers or reading is unavoidable, ensuring that your child takes frequent breaks to rest eyes. Take a break to rest the eyes every 30 to 40 minutes. Look out of the window at distant objects to relax the eyes.
• Hold any reading material 30 cm away from the eyes and always read while sitting upright
• Be seated at least 2 metres away when watching television
• Computer screens or tablet should be placed 50cm away from eyes and adjusted for minimal glare
• Lighting should be sufficient to illuminate the room when reading, watching television or using the computer and tablets

More outdoor and physical activities

Findings from the Singapore Cohort Study of the Risk Factors for Myopia revealed that outdoor activity could be protective against the development of myopia in children.

The Sydney Myopia Study presented in 2006 found that the prevalence of myopia in 6 and 7 year old of Chinese ethnicity in Sydney was 3.3% as compared to that of 29.1% in SIngapore. The main reason for this difference was that children in Sydney spent about 4 times more outdoors than Singapore children, and less or hardly any time on tuition.

Regular outdoor time of 2 hours a day in young children prevents myopia and its progression by about 10-20%.

Early detection

Now with your best efforts to practise good eye care habits and adopting more outdoor activities, your child may still develop myopia. The next best thing you can do for them is to detect it early and slow down the progression. This can be done through yearly eye examinations.

Corrective visual aids like spectacles when used early and appropriately can help the eyes focus better.

There are also some interventions which can slow down the progression of myopia. Some examples include atropine eyedrops and the use of special daily disposable contact lens.

Take note that myopia cannot be prevented or improved by these methods

• avoiding the use of spectacles
• reducing the power of your glasses or under correcting your child’s vision
• taking dietary supplements like vitamin A
• eye exercises, acupressure or vision training.

If ever in doubt, check with your family physician or eye specialist.