Some of the causes of myopia nearsightedness are hereditary, environmental factors, eyestrain and eye structure.
Number of people with myopia has increased significantly among children. For instance, in Singapore, the rate of myopia among school going child is about 75%, up from about 25% in 30 years ago.
Nearsightedness causes
- Hereditary or genetics - Myopia is common where one parent has myopic and much more common with both the parents have been myopic. That is genetic plays an important major role in the causes of nearsightedness or myopia.
- Environmental factors - are also crucial for the causes of myopia. For instance, some medical studies show the percentage of myopia is high in urban population when compared with rural population.
- Eyestrain - Chances of having myopia is increases with the increased hours of close up work such as; reading books, spending most of the time in front of computer, and watching lengthy TV shows.
- Eye structure - Most myopic’s has larger, longer eyeballs. It may be that close work requiring intensive focusing in the young developing eyeball causes it to elongate.
- Food habits - Eating too much of refined white flour increased the chances of nearsightedness.
- Children who play sports have lower chances of myopia, maybe they use more distance viewing and low close up works.
- Other health problems - Some people may experience blurred distance vision only at night. This night myopia may be due to the low level of light making it difficult for the eyes to focus properly or the increased pupil size during dark conditions, allowing more peripheral, unfocused light rays to enter the eye.
- Symptoms of nearsightedness may also be a sign of variations in blood sugar levels in persons with diabetes or an early indication of a developing cataract.
- People whom do an excessive amount of near vision work may experience false or pseudo myopia. Their blurred distance vision is causing by over use of the eyes focusing mechanism. After long periods of near work, their eyes are unable to refocus to see clearly in the distance. The symptoms are usually temporary and clear distance vision may return to normal after eye resting. However, over time constant visual stress may lead to a permanent reduction in distance vision.
An optometrist can evaluate vision and determine the cause of the vision problems.