What Is Myopia? Causes, Symptoms & Treatment
Do you find it easy to read a book up close but difficult to read what’s written on a distant whiteboard? Chances are you have myopia.
Also known as nearsightedness, myopia is a common vision disorder among children and young adults. In adults, it can appear as a result of visual stress. It affects over 27% of the world’s population, and is constantly on the rise.
Myopia can easily be treated. You can wear eyeglasses or contact lenses, and even opt for laser surgery. There are also several ways to better your eye health and prevent your myopia from getting worse.
Read on to learn more about myopia, its symptoms, causes, risk factors, and how it can be treated. Plus, a bonus list of superfoods to protect your vision.
What Is Myopia?
Myopia means shortsightedness. It makes focusing on distant objects difficult, while objects that are nearer appear clear.
Myopia occurs when either the eyeball is too long or the cornea (the protective outer layer of the eye) is too curved. This prevents the eye from bending the light correctly.
There are different types of myopia, including simple, high, pathological, and progressive myopia. Let’s take a closer look at each of these.
Simple myopia is the most common of all. In this, the myopia is typically less than -4.00 to -6.00 diopters. Simply wearing glasses or contact lenses can correct the vision.
This is a more severe form of myopia, and is usually defined as -6.00 diopters or higher. High myopia may lead to eye health complications like retinal detachment, glaucoma, or cataract.
Pathological myopia is also known as degenerative or malignant myopia. It generally occurs when high myopia progresses rapidly. It can lead to retinal issues like lattice degeneration, retinal atrophy, and Forster-Fuchs’ spot, a type of macular degeneration.
In this, myopia continues to worsen year after year. It occurs because of the continuing elongation of the eyeball. Progressive myopia may also develop into high myopia. But control methods like orthokeratology can help slow or halt the condition.
What Are the Symptoms of Myopia?
Myopia symptoms may vary from person to person. Symptoms generally occur during one's school years, but you may also first experience them as an adult.
Some common symptoms of myopia include:
- Difficulty in seeing distant objects
- Constant headaches and eye strain
- Squinting to focus better
- Eye fatigue when trying to see objects at a distance
- Excessive blinking and/or rubbing of eyes
The American Academy of Ophthalmology suggests that these symptoms may be more obvious in children between ages 8 to 12.
If you or your child are experiencing any of these symptoms, it's a good idea to visit an optometrist. They will examine the eye to determine the degree of your myopia and help correct the vision.
What Causes Myopia?
There are two major myopia causes—the eye is too long or the cornea is too curved.
Either of these can cause a refractive error. That means, when light enters the eye, it’s focused in front of your retina instead of on the retina. This results in blurred vision of distant objects.
The Cleveland Clinic notes that myopia can also get worse with age. This is especially common during the adolescent years when the body grows quickly.
Risk Factors for Myopia
Certain risk factors may increase the likelihood of developing myopia. Let’s take a closer look at them.
Myopia tends to run in the family. You are likely to develop it if one of your parents is nearsighted. The likelihood is higher if both your parents are nearsighted.
Certain diseases, like diabetes, can also affect the health of your eyes and lead to myopia. Even a diet poor in vitamins and nutrients can cause a blurry distant vision.
- Environmental Factors
Some studies show that spending little time outdoors may increase the chances of developing myopia. Other factors, like too much screen time and lack of physical activity, may also trigger myopia.
How Is Myopia Diagnosed?
Your optometrist can diagnose myopia by performing standard eye exams. This will involve reading letters of different sizes from a chart at a distance of 6 meters.
They will then use a lighted retinoscope and measure how light is reflected by your retina.
Finally, they will use a phoropter, a tool to measure and correct the refractive error by placing different lenses in front of your eyes.
There are several myopia correction and treatment options. You can correct your myopia by using eyeglasses or contact lenses. Different refractive surgeries can correct the condition, such as LASIK and PRK. Let’s understand all these different treatment options in detail.
Eyeglasses are the most common corrective option for myopia. Depending on the degree of myopia, you may need to wear your eyeglasses either daily or only when you need distance vision.
Generally, a single-vision myopia lens is prescribed to make distance vision clearer. But in certain cases (like in adults over 40 years), a bifocal or progressive lens may be needed.
Contact lenses are transparent disks that sit on the eye’s surface. If you don’t like the look or feel of glasses, you can opt for contact lenses.
Many people also find their distance vision sharper and wider with contact lenses. But since these are worn directly on the eyes, it’s important to change and clean them regularly.
Orthokeratology (Ortho-k) is also called corneal refractive therapy (CRT). This is a non-surgical procedure to reshape the cornea temporarily.
You will have to wear rigid contact lenses, often even at night. These lenses will put pressure on the cornea and help reshape it. This will further change how light focuses on entering the eye.
This procedure is recommended for some people with mild myopia. But it also carries risks of eye infections.
LASIK, or laser-assisted in-situ keratomileusis, is a surgical procedure to correct myopia. In this, the surgeon will cut a flap through the top of the cornea using laser. They will sculpt the corneal tissues with a laser beam of light and then drop the flap back into its place.
LASEK, or laser-assisted subepithelial keratectomy, is another surgical option for myopia. It involves cutting the flap through only the top (epithelium) layer of the cornea, reshaping the outer layers, and then closing the flap.
In PRK, or photorefractive keratectomy, your surgeon will use laser to remove a very thin layer of tissue from the surface of the cornea. This will flatten the cornea and help refocus light entering the eye. Unlike LASIK, PRK does not involve cutting a flap. It's a preferred option for people with thinner corneas.
This is an option for myopia patients with corneas too thin for PRK or LASIK. In this, intraocular lenses are implanted in the eye, just in front of the natural lens.
Vision therapy helps strengthen the muscles through eye exercises. It’s especially useful when spasms of the focusing muscles cause myopia. The muscle exercises help regain focus and sharpen distance vision.
How to Prevent Myopia from Getting Worse
Your myopia does not have to get worse every passing year. Make these following steps into everyday habits, and see the difference.
- Limit your screen time. Avoid mindless scrolling on your social media platforms.
- If you work on a computer, take regular screen breaks. You can try the 20-20-20 rule. Look 20 feet away every 20 minutes for about 20 seconds.
- Go for regular eye exams. These will help correct your vision early on and also spot diseases, should there be any.
- Read or work in a well-lit area. Dim lighting can strain your eyes and speed your myopia.
- Quit smoking. Smoking can damage your optic nerve, cause macular degeneration, cataracts, and other eye health problems.
- Wear sunglasses outdoors. They will protect your eye from the harmful ultraviolet rays.
- Use protective eye gear when necessary, especially while playing sports like ice hockey, where the risk of eye injury is high.
Superfoods for Healthy Eyes
Though there’s no cure for nearsightedness, there are several superfoods that can keep your eyes healthy. Include these in your everyday diet and prevent your myopia from advancing.
- Berries and Citrus Fruits: Berries and citrus fruits contain phytochemicals and Vitamin C. Regularly eating these will strengthen your immune system and protect your eye against eye infections and diseases. Blueberries and goji berries can be especially beneficial for eye health.
- Fish: Salmon, tuna, and sardines are a great source of omega-3 fatty acids. They help prevent dry eye syndrome.
- Green Vegetables: Leafy green vegetables like kale and spinach are rich in lutein. It helps the eye filter the harmful blue light that can damage the retina.
- Eggs: Rich in Vitamin A, eggs can reduce the risk of age-related vision problems.
- Carrots: Carrots contain both Vitamin A and beta carotene. These lower your risk of diseases like macular degeneration, glaucoma, and cataract.
- Nuts: Include nuts like almonds, walnuts, and pistachios in your diet. These contain high levels of Vitamin E, which may help preserve your eyesight.
- Dark Chocolate: Studies suggest that consuming dark chocolate can improve your eye health. It also betters your visual clarity and contrast sensitivity.
Given that myopia has genetic links, there’s not much you can do to prevent it. But certain steps can help slow its progression.
Start by making changes in your lifestyle and habits. Spend more time outdoors while trying as much as possible to minimize time spent in front of a computer, smartphone, tablet, or computer.
You can also make your diet more nutrient-rich. Fruits, vegetables, and nuts in your everyday meal will keep your eyes healthy. Choose fruits like berries to max out on some of the best nutrients for eye health.
Wear sunglasses outside, and protect your eyes from harmful chemicals and irritants. Additionally, make sure to wash your hands well while wearing contact lenses.
Just a few but important steps can better your eye health and keep myopia from progressing.
Take the Dry Eye Test
People with myopia may be at a higher risk of developing dry eye symptoms. This may happen after LASIK treatment, which compromises tear function for at least 6 months after surgery.
What's more, according to a 2014 study, people with pathologic myopia have a higher Ocular Surface Disease Index (OSDI) score than those who don’t have the condition. At the same time, they have a lower tear break-up time, which indicates a poor tear film. The same source notes that women with myopia are at a higher risk than men to experience dry eye symptoms.
Do you think you may have dry eyes? There’s a quick and easy way to test your OSDI score.