WHAT CAUSES MYOPIA
Updated: Apr 17
Myopia, commonly known as nearsightedness, is a refractive error of the eye that causes distant objects to appear blurry, while nearby objects remain clear. Myopia is a common condition that affects millions of people worldwide, and its prevalence is increasing rapidly, particularly in urban areas of developed countries. The exact cause of myopia is not fully understood, but it is thought to be the result of a combination of genetic and environmental factors.
In this article, we will explore the causes of myopia and the factors that contribute to its development.
Elongation of the Eyeball
One of the main causes of myopia is an elongation of the eyeball. In a normal eye, light passes through the cornea and lens and focuses directly on the retina at the back of the eye. In a myopic eye, however, the eyeball is elongated, causing the focal point of light to fall in front of the retina rather than directly on it. This results in blurred vision when looking at distant objects.
Refractive Errors in the Cornea or Lens
Another cause of myopia is a refractive error in the cornea or lens. This can occur if the cornea or lens is not perfectly curved or if it is too thick, causing light to be refracted incorrectly. In some cases, myopia may also be caused by abnormalities in the shape of the lens, such as a cataract, which can cause light to scatter and result in blurry vision.
Genetics and the Inheritance
Genetic factors are also believed to play a role in the development of myopia. Studies have shown that if one or both parents have myopia, their children are more likely to develop the condition. However, the specific genes responsible for myopia are not yet fully understood. Some studies have suggested that genes involved in eye development and growth may play a role, while others have pointed to genes that control dopamine signaling in the eye.
The Impact of Work on Eye Health
One of the most widely studied factors is near work, such as reading, writing, and using digital devices. Studies have shown that prolonged periods of near work can lead to changes in the shape of the eye, causing it to become elongated and leading to myopia. This is thought to occur because when we focus on near objects, the ciliary muscles in our eyes contract, which causes the lens to become more convex, increasing the refractive power of the eye. Over time, this can cause the eyeball to elongate and result in myopia.
Environmental factors are also thought to contribute to the development of myopia. One of these factors is reduced time spent outdoors. Several studies have shown that children who spend more time outdoors are less likely to develop myopia than those who spend more time indoors. This is thought to be due to the beneficial effects of natural light on the eyes. Exposure to sunlight may help to regulate the growth of the eyeball and prevent it from becoming elongated.
Age and Gender
Other factors that may contribute to the development of myopia include age, gender, and ethnicity. Myopia is more common in children and young adults, and it tends to stabilize as a person reaches their mid-20s. Women are also more likely to develop myopia than men, although the reasons for this are not yet fully understood. Myopia is also more common in certain ethnic groups, such as Asians, who have a higher prevalence of the condition compared to other populations.
In conclusion, myopia is a common condition that affects millions of people worldwide. While the exact cause of myopia is not fully understood.
Regular eye check-ups as directed by your eye doctor can also help catch any early signs of myopia, so you can get treatment as soon as possible.