If you’ve ever looked up from a few hours of focused computer work, or torn yourself away from a compelling book, you may have noticed that things far away from you are blurry. This doesn’t always last, but for people with nearsightedness, their faraway vision is fuzzy all the time.

Nearsightedness, also known as myopia, is a very common condition in which things close to you are clear, but anything a certain distance away is blurry. Below, we’ll talk about what causes myopia, how it changes throughout your life, and what you can do to maintain your vision.

Making sense of myopia (nearsightedness)

Myopia is a common eye problem that impacts distance vision. People with myopia are able to view things clearly when they are close, but struggle to see things that are far away, such as the white board in a classroom or the signs on a highway.

Myopia is caused by a structural issue within the eye that develops during childhood. An eye with perfect vision is shaped a certain way so that the natural focal point of light is directly on the retina, or the tissue at the back of the eye that sends information about what we’re seeing to the brain. But when the eyeball grows into an oval shape or the cornea develops an excessive curve (becoming myopic), light that enters the eye hits the wrong focal point, which causes images to be unclear or blurry.

Think of a movie being projected off center on the big screen – this is known as a refractive error. With myopia, the light that enters the eye is focused in front of the retina, rather than directly on the retina itself.

Myopia symptoms affect our vision and more

The symptoms of myopia can be pretty clear (no pun intended). But blurry vision is a symptom of several other eye conditions, so you’ll want to watch for these specific signs:

• Blurry distance vision – Objects close to you are clear, so you don’t have trouble reading words in a book or on a computer screen when they’re right in front of you. But when you step back from them, the text starts to blur. Many people notice their blurry distance vision when watching a movie at the theater, seeing a play or musical, or navigating with street signs. School-aged children with myopia often have trouble seeing the whiteboard, depending on where they sit in the classroom.
• Squinting to see clearly – If you have myopia, you may have already noticed that your distance vision becomes clearer when you squint. There are two reasons for this. One is that the act of squinting actually changes the shape of your lens and eyeball by a small amount, enough to reduce the refractive error. The second reason is that squinting limits the amount of light entering your pupil, allowing your eye to focus better.
• Eye strain – When we’re looking at something up close, whether reading, texting, writing, drawing or typing on the computer, our eyes are working hard to keep it in focus. After several hours of uninterrupted visual focus, your eyes can get tired and start to feel sore. This is eye strain. It’s not technically a symptom of myopia, but rather a co-occurring condition. Both myopia and eye strain are exacerbated by near work.

The types of myopia come with different health considerations

If you’ve worn glasses or contact lenses before, you may have noticed that your eyes were assigned either positive or negative numbers on your prescription. These numbers are diopters, which eye specialists use as their unit of measure in determining the extent of your refractive error, and thus the type and amount of vision correction you need. Farsightedness is measured in positive diopters, and nearsightedness is measured in negative diopters.

The amount of nearsighted vision correction you need will categorize your myopia as either non-pathologic, high or pathologic.

Non-pathologic myopia

Non-pathologic myopia ranges from more than 0 to less than -6 diopters. This type of myopia, also called simple or school myopia, can be easily corrected through standard treatments, like eyeglasses, contact lenses or refractive surgery.

High myopia

Myopia with a refractive error of more than -6 diopters is considered high myopia. High myopia can be corrected with eyeglasses or contact lenses, but not most refractive surgeries because of an increased risk of complications. Eyes with high myopia are very long, and this structural stretching can cause several serious eye conditions. High myopia is often accompanied by pathologic myopia, but not always.

Pathologic myopia

Also called degenerative myopia, pathologic myopia leads to serious eye complications in adulthood, like retinal detachment, myopic maculopathy, glaucoma and blindness. An earlier onset of myopic symptoms in children can predict pathologic myopia later in life.

Visit an eye doctor right away if you experience sudden onset myopia accompanied by flashers and floaters or loss of vision in one eye. This could signal a more serious health problem.

Myopia is one of many different types of refractive errors

All refractive errors originate from an irregular eye shape. But how do you tell the difference between them? Here is how myopia compares to a few other common refractive errors:

• Myopia vs. hyperopia – Where myopia is nearsightedness, hyperopia is farsightedness, or the inability to see things clearly when they’re close to you. The two conditions are opposites in every way. Farsightedness is the result of an eyeball that is too short or a cornea with too little curve, and light projects behind the retina instead of on it.
• Myopia vs. astigmatism – Astigmatism is another type of blurry vision caused by an irregular eye structure. In the case of astigmatism, the cornea or lens isn’t a uniform sphere all the way around. They’re shaped more like a football.
• Myopia vs. presbyopia – Presbyopia is the term for age-related farsightedness. Around our early to mid-40s, we start to lose flexibility in the lenses of our eyes, and that makes it harder for us to focus on near objects. This structural change in the eyes happens to everyone, regardless of family history or individual eye shape. It’s a normal part of the aging process.

Visiting an optometrist is the best way to find out if you have a specific refractive error and to learn how to address it. An optometrist is an eye and vision specialist that evaluates your vision and the health of your eyes, so you can get the best treatment for you.

Nearsightedness has more causes than too much “near work”

Near work – which is any task that requires prolonged focus on something (i.e., a book, a computer screen, a journal, a drawing) closer than arm’s reach – is nearly unavoidable in our modern world. While myopia has been around as long as humans have, the rise of technology has triggered a rise in myopia. Current research shows that by the year 2050, more than half of the world’s population could be myopic. In response, the World Health Organization identified myopia as a global public health crisis in 2018.

Myopia is most often associated with childhood because that’s when it first appears. Children who spend too much time on near-work activities or don’t spend enough time outside can become myopic. There’s also a genetic component, and the child of one or both parents with myopia has a higher chance of being myopic themselves.

However, myopia is not just for children. Adults who were not myopic in their younger years can still experience blurry distance vision later in life due to prolonged near-work tasks, as well as:

• Unmanaged diabetes – Fluctuating blood sugar levels, associated with diabetes that is not being managed, can affect eye health and lead to different refractive errors, including myopia.
• Cataracts – Developing cataracts tends to precede the development of myopia. In this case, it’s known as lens-induced myopia. Undergoing cataract surgery at a young age can also increase the likelihood of myopia later in adulthood.
• Eye injury – Following a blow to the head or eye area, you may experience sudden or delayed changes to your distance vision. This is known as traumatic myopia. In most cases, it only lasts as long as the healing process. But it can be permanent, depending on the injury.
• Eye disease and infection – Eye inflammation, a common side effect of many diseases and infections, can cause myopia. For example, chronic inflammation of the inner eye, medically known as uveitis, can lead to acute or chronic myopia.
• Computer vision syndrome – Also called digital eye strain, computer vision syndrome occurs after long, uninterrupted stretches of time spent staring at a screen, or staring at screens frequently. It causes headaches, eye strain and blurry vision. Over time, it can worsen any existing refractive errors.

Myopia is commonly diagnosed in people before they reach the age of 20. In fact, approximately 75% of patients with myopia are diagnosed between the ages of 3 and 12. Once the eye has begun to grow in a myopic shape, it will continue to do so. A 2022 study showed that the fastest progression of myopia occurs between ages 7-12, which is a common period of rapid growth for children.

Myopic progression then slows down through the teenage years and eventually stabilizes around age 20, when our eyes have finished growing. However, around 40% of people with myopia will still experience worsening vision in their 20s and 30s.

What you can expect from myopia treatment and control

After your eyes have finished developing, which typically occurs around age 20, the focus of myopia control becomes maintaining the level of vision you have. Your eye doctor may suggest:

• Eyeglasses or contact lenses – Depending on the severity of your myopia, you may not need to wear eyeglasses all the time. If you do, you can opt for contact lenses. Your prescription should remain relatively stable throughout your adult life. You can opt for special contact lenses that temporarily reshape your cornea when worn during sleep, allowing for clear vision throughout the day. This is called orthokeratology, and it uses ortho-k contact lenses.
• Refractive surgery – Surgical treatment for myopia is not recommended for anyone under 18, while the eyes are still growing. Once your optometrist has determined that your eyes have fully developed, they may recommend you talk with an ophthalmologist about refractive surgery. Photorefractive keratectomy (PRK) and LASIK eye surgery are well-known types of refractive surgery for myopia.

Protecting your eyes and controlling myopia naturally

While your eye doctor can help manage your myopia with vision correction or medical interventions, there are other things you can do on your own to maintain your eyesight.

To preserve and strengthen the health of your eyes, try these tips:

• Take regular breaks from near work – During your workday or while focusing on your favorite hobby, look up and away toward something that is at least 20 feet away about every 20 minutes for at least 20 seconds. You can set a timer to remind yourself. These breaks also offer you a chance to stand up and move your body. Even a few minutes of stretching or a short walk can have huge benefits for your physical health.
• Spend time outside – A 2015 study published in the Journal of the American Medical Association, found that at least 90 minutes of outside time each day is optimal for eye health, especially children’s eye health. If it’s sunny, be sure to wear sunglasses with UV protection.
• Eat an eye-healthy diet – Look for food rich in vitamins and minerals that support eye health, like vitamin A, vitamin C, vitamin D and lutein. Incorporate plenty of carrots, sweet potatoes, beans, citrus fruits, avocados, white fish and leafy greens into your diet. The good news is that eye-healthy foods are also healthy for your whole body, including your heart health.
• Don’t smoke – Smoking can have a very negative impact on the health of your eyes. When you smoke, you increase your risk of developing serious eye conditions, like macular degeneration, retinal detachment, cataracts and glaucoma. You raise the risk of everyone around you too, through secondhand smoke.

Visit HealthPartners eye care to learn more, or schedule an appointment with our optometrists to get started with your vision care.