Myopia (the medical term for nearsightedness) is very common - so common that it affects nearly 30% of the U.S. population. It occurs if the eyeball is too long or the cornea (that little clear front cover of the eye) is too curved. As a result, the light entering the eye isn’t focused correctly and distant object will look blurry. Although myopia can be corrected with glasses, contact lenses or surgery in some cases, having myopia can increase your chances of having more severe eye problems later in life, i.e. cataracts, glaucoma, and retinal detachment.
Unfortunately myopia is becoming more prevalent in children, which can have an impact on their education and future prospects. This condition can be inherited, or it can be caused by lifestyle habits and tends to worsen as we grow older, or as a child’s eyes continue to grow as well. Identifying the risk of myopia and acting early can help prevent or delay the progression of the condition through myopia control.
What Causes Myopia Progression?
The main cause of myopia progression is an increase in the eye’s axial length - but what does that really mean? The axial length of the eye is the distance between the anterior (the front side of the eye) and posterior (the back side of the eye) poles. A myopic eye focuses an image at the front of the retina, instead of directly on the retina, causing blurry distant vision.
Many factors can contribute to this:
Wearing glasses all day, everyday could potentially lead to myopia worsening. If it’s a case of low myopia, glasses should only be worn sometimes, for activities such as watching TV or playing sports. Glasses for low myopia are not needed for near vision tasks, such as reading, writing, or completing homework. If it’s a case of moderate to high myopia, you’ll need to wear your glasses for both near and distant vision, so in this case, this factor cannot be controlled.
Wearing glasses with full correction may also contribute to myopia progression. Try a prescription that under-corrects - although the full correction will provide significantly clearer vision, it can also contribute to myopia worsening over time.
Natural eye growth causes myopia to worsen as the eye grows and changes shape. Myopia tends to progress and worsen through the teenage years and plateaus by the time you reach 20 - that’s typically the time the eye stops growing.
Genetics contribute to myopia progression, especially if both parents are myopic.
Limited outdoor time has been shown by research to cause myopia progression, mainly if you spend less than 102 hours outside per day. Outdoor time is essential for children with myopia as it gives the eye muscles a chance to relax and take a break from constant focusing activities.
Prolonged use of digital devices has been linked to myopia progression. Spending many hours on all different types of devices - smartphones, tablets, computers, etc. Prolonged usage of digital devices can place excessive stress on your ability to focus and can lead to eyestrain and myopia progression.
Prolonged near vision tasks of any kind - reading, writing, computer use, smartphone use, etc. has been shown to be a possible cause of myopia progression.
Although there isn’t a cure for myopia, it can be controlled and/or managed to a certain extent.
Why Is Myopia Control So Important?
Early myopia onset can lead to a faster rate of progression and a greater final degree of myopia (on a scale from low to high). The long-term risks associated with myopia progression are important to understand and in order to preserve your ocular health, you should discuss the long-term risk of myopia with your doctor. Below are some of the important long-term risks of myopia.
Glaucoma
There is a clear correlation between patients being diagnosed with myopia and the development of glaucoma. This occurs because myopia causes structural changes to the eye such as an increase in the retinal nerve fiber layers. This leads to thickening of the macula which can facilitate the onset of glaucoma.
Cataracts
While the exact cause of why highly myopic patients are at a greater risk for developing cataracts is still being investigated, researchers suggest that the increasing axial eyeball length in myopic eyes may prevent nutrient delivery to the back side of the lenses. As a result, they lose their clarity and begin forming cataracts.
Retinal Detachment
In highly myopic people, retinal thinning can occur with age causing tears and holes which can lead to retinal detachment.
Macular Degeneration
As your eyes grow more myopic, cells in the center of the retina can become affected causing a blind spot in the center of the eye. The thinning of the back of the eye can also cause cracks in the deeper layers under the retina leading to further atrophy or bleeding in the center of the macula.
Refractive Surgeries
High myopia reduces the possibility of being a candidate for refractive surgeries such as LASIK and increases the risk for complications from these treatments, causing unpredictable results.
Blindness
According to estimates by the World Health Organization Global Burden of Disease program, uncorrected distance refractive error (myopia) is the second largest cause of blindness and the leading cause of moderate and severe vision impairment. Degenerative myopia causes progressive stretching and gradual damage of the retina, choroid, vitreous, sclera, and optic nerve.
Adjust The Factors You Can Control
Decrease the duration of near vision tasks and activities, or at least make sure you take frequent breaks - give your eyes a rest.
Go outside everyday for at least 60-80 minutes to give the eye muscles a chance to relax.
Schedule regular eye exams with your doctor to ensure you’re taking the steps in the right direction.
Doctor Guided Myopia Control
Sometimes adjusting those things you can control just isn’t enough and you need a little extra boost - your doctor can help with myopia control and management.
Low-Dose Atropine Eye Drops
Remember those drop your doctor uses to dilate your eyes before your exam? Well, when used in small doses, the drops slow the progression of myopia by keeping the eye from lengthening too much.
Multifocal Contact Lens
These special contact lenses provide different areas of focus. Think of this type of lens as looking like a dartboard with multiple circles inside of each other. The center of the lens, of the “bull’s eye”, corrects blurry distance vision, while the outer portions of the lens defocuses or blurs the peripheral (side) vision. Blurring your peripheral vision is though to slow eye growth and limit myopia.
Corneal Retractive Therapy (CRT Lens)
This contact lens is one that’s worn overnight to correct blurry distance vision during the day It flattens your cornea while you sleep and the next day, as light passes through the reshaped cornea, it falls precisely on the retina making distant images appear clearer. These lenses will improve vision for a short period of time, however once you stop wearing the lenses, the cornea slowly goes back to its normal shape and myopia will return.
Myopia is often not taken seriously because many of the risks are associated with high myopia - yet it’s important to take the steps necessary to control its progression as early as possible. If left to progress without proper action and attention, myopia can lead to serious vision-related conditions later in life.
Dr. Sandra H. Barker, O.D. F.A.A.O.
Eye Associates of Winter Park, P.A.
Dr. Sandra Barker is a Board Certified Optometric Physician. She received her Bachelor’s degree in Biology with Honors from the University of Texas at Austin. She received her Doctor of Optometry degree from the University of Houston College of Optometry. After completing her internship in the Optometry/Ophthalmology Service at Walter Reed Army Medical Center in Washington, D.C., Dr. Barker practiced for two years in Houston prior to co-founding Eye Associates of Winter Park with her husband, Dr. Gary Barker, in 1985.
While Dr. Barker sees patients of all ages for comprehensive eye care, her area of expertise is specialty contact lenses including Corneal Refractive Therapy and contact lenses for patients with diseased corneas such as keratoconus or post-refractive surgery complications.
Dr. Barker is a Fellow of the American Academy of Optometry, a member of the Central Florida Society of Optometric Physicians, the Florida Optometric Association, and the American Optometric Association.
