Myopia, commonly known as nearsightedness, is a condition that affects the eyes and their ability to focus on distant objects. It is the most common eye disorder in the world, affecting nearly a third of the population. While it can be corrected with glasses or contact lenses, it can also lead to vision complications in later life if not treated early.
Myopia occurs when the eyeball is too long, or when the curvature of the cornea is too steep. The eye is unable to focus the light rays correctly on the retina, resulting in blurred vision when looking at distant objects. Close objects, such as a book or computer screen, appear clearer.
Causes of Myopia
Genetic factors are one of the most common causes of myopia, with an estimated 40 to 60 percent of cases being genetically inherited. In these cases, myopia is caused by the eye’s shape, which is determined by our genetic makeup. The eye’s shape can cause a decrease in the eye’s ability to properly focus light onto the retina, resulting in blurred vision.
Environmental factors can also play a role in the development of myopia. One environmental factor is increased time spent indoors, as exposure to natural light is important for proper eye development. Additionally, prolonged periods of reading or computer use can also contribute to myopia. Finally, a diet low in Vitamin A can also lead to myopia due to a decrease in the eye’s ability to properly focus light.
Lifestyle choices can also have an effect on myopia. Smoking, for example, has been linked to an increased risk of myopia. Additionally, those who spend more time in front of the computer or television are more likely to develop myopia. Pregnant women should be especially careful, as some studies show that a lack of certain nutrients or exposure to certain environmental toxins can increase the risk of myopia in unborn children.
Symptoms of Myopia
Although myopia typically begins during childhood, it can develop at any age due to a number of underlying genetic and environmental factors. The severity of myopia can range from mild to severe, so it’s important to understand the symptoms in order to seek the appropriate treatment. Here’s a look at the most common symptoms of myopia.
Blurred vision at a distance. One of the most telltale signs of myopia is blurred vision when viewing distant objects. People with myopia may have difficulty reading street signs, recognizing faces from far away, or seeing the board in a classroom.
Squinting. If you or your child is squinting in order to see distant objects more clearly, myopia may be the culprit.
Headaches. People with myopia may also experience headaches as a result of constantly trying to focus on distant objects.
Eyestrain. If you’re feeling tired or fatigued after spending a long time looking at distant objects, myopia could be the cause.
Difficulty driving. Driving at night can be especially challenging for people with myopia due to decreased visibility.
Frequent changes in prescription. If your prescription for glasses or contact lenses changes more often than normal, myopia could be the culprit.
Diagnosis of Myopia
Myopia can be diagnosed with a comprehensive eye exam. This includes tests to measure the refractive error, which refers to how well the eye focuses light. The doctor may measure the curvature of the cornea, the size of the eye, and the amount of light that is focused by the lens. An auto refractor is used to measure the eye’s refractive error, and a retinoscope is used to measure the curvature of the cornea. The doctor may also use a phoropter, which is a device used to determine the prescription for eyeglasses or contact lenses.
The doctor may also perform a visual acuity test, which measures how well the patient can see at different distances. This is done by having the patient read letters on a wall chart. If the patient has difficulty seeing the letters, then they are considered to be nearsighted.
Prevention of Myopia
While there is no cure for myopia, there are steps that can be taken to prevent it and slow its progression.
The first step to preventing myopia is to ensure that your child is getting regular comprehensive eye exams. Typically, this means a visit to an optometrist or ophthalmologist at least once a year. During the exam, the eye doctor will check the vision of the patient, their eye health, and the development of any eye-related conditions. Early detection of myopia is key for successful treatment.
Another important step for preventing myopia is to make sure your child is getting enough time outdoors. Studies have shown that spending time outside in natural light can reduce the risk of myopia. The American Academy of Ophthalmology recommends that children spend at least two hours outdoors each day. The sunlight helps to regulate the eyes’ focus, which can reduce the risk of myopia.
Regular exposure to bright indoor lights can also help prevent myopia. Studies have shown that exposure to bright lights can reduce the risk of myopia, so it is important to ensure that your child is exposed to bright lights during their activities. It can also be helpful to limit the amount of time your child spends looking at screens, such as TVs, phones, and tablets. Too much screen time can lead to eye strain, which can contribute to myopia.
Treatment of Myopia
Myopia can be treated with a variety of methods, although the most common is with corrective lenses. Glasses or contact lenses can correctly refocus the light that enters the eye, allowing for clear vision. The lenses come in a variety of strengths, and the optometrist or ophthalmologist will provide the appropriate lenses for the individual’s prescription.
Another option for treating myopia is refractive surgery. This is a surgical procedure that changes the shape of the eye, and can help to reduce or eliminate the need for glasses or contacts. Laser eye surgery, Photorefractive keratectomy (PRK), and LASIK are all types of refractive surgery that are used to treat myopia. Each of these techniques has its own advantages and drawbacks, and the individual should discuss the pros and cons of each with their doctor before making a decision.
The third option for treating myopia is Ortho-K lenses. These are special contact lenses designed to reshape the cornea while the person sleeps, improving vision during the day. Ortho-K lenses are usually worn overnight and removed in the morning, and the results may last for up to two weeks. This type of treatment is often used for people who have a mild form of myopia and have difficulty adapting to corrective lenses.
Finally, there is a relatively new treatment for myopia known as Orthokeratology. This technique uses gas-permeable contact lenses that are designed to reshape the eye while the person sleeps. The lenses are worn overnight, and the results can last up to three months. This type of treatment is often used in cases where glasses or contacts cannot provide adequate vision correction.