Short-sightedness is also called myopia. This eye condition causes objects at a far distance to appear blurred, but the affected person can see close objects clearly. Short-sightedness usually occurs when the eyes grow bigger than the size of those who can see well at all distances. In the UK, about one in six persons (17.8%) have myopia.
In most cases, myopia sets in within school age, about 6 – 14 years, and the condition progresses in the teenage years when rapid growth occurs, and the eye focuses more on near work. The condition then stabilises in the early adult years.
The severity and degree of myopia vary between people, and it ranges from mild to high myopia, where the vision is significantly affected.
What causes short-sightedness?
The exact cause of myopia is not fully clear, but several studies are ongoing to determine the cause of this eye condition. However, experts suggest that environmental and genetic factors contribute to the development of myopia.
The prevalence of short-sightedness varies amongst different geographic and ethnic populations, and people in East Asia have the highest occurrence of myopia.
Some studies suggest that a child’s risk of developing myopia increases with having parents suffering from this eye condition. This means that the probability of developing myopia with one parent who has the condition is double compared to children who do not have parents with myopia and about eight times higher for children whose both parents have myopia.
Although genetic factors may affect the development of myopia, the increase in the number of people with myopia over the years suggests that environmental factors such as the number of outdoor activities engaged in and near work significantly affect the occurrence of myopia.
How do the eyes react?
When you look at a close object, the eyes adjust and focus the near object for the image to form at the back of the eye (retina). This allows us to see the object. In some cases, the eyes may not meet the focus needed,resulting in a blurred image behind the retina.
In this case, the body will try to focus the image correctly by elongating the eyes to allow a clear image form. However, this reaction may be counterproductive, causing a progression in the level of short-sightedness.
Activities like close distance reading, continuous reading and near work cause progression in myopia. Some studies of people with over ten years of education are likely to have longer eyes of about 0.60mm.
The importance of spending time outdoors
Research has shown that outdoor activities have a link to lower levels of short-sightedness progression. These studies show that focusing on distant objects for 2 – 3 hours. Combat the effect of carrying out near work for 9 – 12 hours.
Furthermore, some studies demonstrated that exposure to natural sunlight could stimulate the retina to release dopamine, preventing eye growth and myopia progression.
Prevalence of short-sightedness
In the UK, myopia affects about 2% of children between six and seven years and 15% of children between 12 – 13 years. Studies show that as the prevalence of myopia increases, the onset of the condition occurs at an earlier age. This allows more time for the degree of short-sightedness to progress into a more advanced stage.
How to avoid short-sightedness
Several methods have suggested to slow down myopia progression, and some have proven to be effective. However, consulting your eye doctor is advisable to know how to prevent myopia progression.
Taking regular breaks when carrying out close-up work by spending time outdoors. And focusing on distant objects can help prevent myopia from progressing. Ensure you get regular eye tests and when you have concerns about your vision if you have myopia.
You can read more about short-sightedness if you experience this eye condition. If you are residing in London, visit Optimal Vision to speak to an eye doctor about your vision problems.