Myopia is the inability to see objects clearly at a distance. It often occurs when the length of the eye causes light rays to bend incorrectly, focusing images in front of the retina instead of reaching the back of the eye.
Myopia may develop gradually or rapidly, often worsening during childhood and adolescence. Early onset myopia is associated with higher amounts of progression and may lead to high myopia. High myopia (greater than -5.00D) is associated with other eye problems such was retinal detachment and glaucoma.
The prevalence of myopia has increased dramatically over the past few decades. Myopia has doubled in prevalence in US children from 20% in the 1990s to 40% in the 2010s. It is anticipated that 58% of the world’s population will be myopic by 2050.
What Causes Myopia?
Both hereditary and environmental factors contribute to the onset and progression of myopia. If one parent is myopic, there is a 25% chance that their child will develop myopia. If both parents are myopic, there is a 50% chance. Studies suggest that screen time and near work increase the risk of myopia. Alternatively, spending at least two hours outdoors daily has proven to prevent the onset of nearsightedness.
What Are Signs and Symptoms of Myopia?
Blurred distance vision is the first symptom of myopia. Small amounts of myopia may not be noticed by your child. Parents should watch for squinting or complaints of blurry vision. They may also notice their child turning their head to the side in order to look out of the corner of the eye. Children do this to create a pinhole effect with their eyelids. This helps focus light entering the eye. It is important to have a comprehensive eye exam before starting school. If there is a strong family history of myopia, an earlier eye exam could be beneficial.
How Is Myopia Diagnosed?
Myopia is diagnosed with a comprehensive eye exam with a cycloplegic refraction. Eye drops are used to relax the focusing system of your child’s eye in order to prevent their eye muscles from straining through the exam. The doctor will hold up different lenses to assess which lens allows the light source to focus on the back of the eye. This allows the eye doctor to accurately measure the glasses prescription.
What Are the Long-Term Effects of Myopia?
Most individuals with myopia simply experience blurred distance vision, which can be resolved with glasses or contact lenses. People with high or progressive myopia (greater than -5.00) are at greater risk for complications including decreased central vision, retinal tears or detachment, glaucoma and cataracts.
How Do I Prevent Myopia from Progressing?
It is not possible to reverse or completely stop myopic progression. Myopia control interventions are focused on slowing down its progression, making individuals less susceptible to complications. Myopia is caused by both hereditary and environmental factors. Hereditary factors cannot be changed. Environmental factors can be altered to minimize myopic progression.
- Maintain a healthy distance when performing near tasks (reading, computer, tablet, phone) by holding reading material at an arm’s length.
- Get outside! Spending two or more hours outside daily helps to prevent the onset of myopia.
- Follow the 20/20/20 rule. Taking frequent breaks while performing near work is important. After every 20 minutes look at something 20 feet away for 20 seconds.
- Keep your glasses updated.
If adjustments to lifestyle are not sufficient, your doctor may recommend one or more myopia control interventions. Your child may benefit from one of the following methods of myopia control:
- Low-dose atropine eye drops
- Peripheral defocus contact lenses
- Combination therapy
Atropine eye drops have historically been used to dilate pupils and treat amblyopia. Studies have found that in extremely low doses, atropine effectively slows down myopic progression. A recent large study found that atropine 0.01% slowed down myopia by 60 percent. Low-dose atropine is not commercially available and must be prescribed through a compounding pharmacy.
Peripheral Defocus Contact Lenses
Peripheral defocus contact lenses are designed to provide clear vision while immediately slowing myopic progression. This novel contact lens design contains treatment zones which remove the stimulus for myopic progression by bringing the object of focus in front of the retina rather than behind it. Clinical studies found myopia to slow by 59% with many patients progressing less than one diopter over a six-year period. This soft daily disposable contact lens is the only FDA-approved method for myopia control.