Understanding and Managing School Myopia: A Clinical Perspective
As an optometrist, one of the most common vision concerns I see in children and teenagers is School Myopia. With the increasing demands of academic work, digital screen use, and reduced outdoor activities, more children are developing myopia at a younger age. Understanding the underlying causes and effective management strategies is essential for providing the best care.
Let me share a detailed, practical overview of school myopia—its causes, progression, and most importantly, how we can manage it effectively.
Types of Myopia
Myopia, or nearsightedness, can be broadly divided into two main categories:
1. Axial Myopia
This occurs when the axial length of the eye—the distance from the cornea to the retina—is longer than normal.
• Corneal Power: 40D
• Lens Power: 20D
• The total optical power remains correct, but because the eyeball is elongated, light rays focus in front of the retina, leading to blurred distance vision.
• Axial myopia is usually congenital and can progress significantly during the growth years.
Management: Axial myopia is challenging to control and typically requires vision correction with glasses or contact lenses. In adulthood, refractive surgeries like LASIK or secondary IOL implants are the only ways to correct it permanently.
2. Refractive Myopia (School Myopia)
This form of myopia is caused not by an elongated eyeball but by changes in the cornea or lens that increase the eye’s refractive power.
• The axial length is normal, but the cornea or lens becomes excessively curved or the lens accommodates excessively.
• Light converges more than necessary, focusing in front of the retina and causing blurred distance vision.
Why is it Called School Myopia?
This condition is commonly seen in school-aged children due to prolonged near work—reading, writing, or using digital screens. Excessive near tasks force the lens to accommodate more than needed, leading to a habit of over-accommodation.
Example:
• Normally, the lens provides about +20D or 5x magnification for near tasks.
• In school myopia, due to continuous strain, it may accommodate excessively to +22D or 5.5x magnification.
• This leads to a hyperopic defocus when looking at distant objects because the extra accommodation causes light to focus in front of the retina.
Correction:
To neutralize this excessive convergence, we prescribe concave (minus) lenses. For example, if the eye is accommodating an extra +2.00D, we correct it with a -2.00D lens. However, this is often a temporary fix because the brain adapts to this over-accommodation. Within a year, the child might need stronger lenses due to the progression of myopia.
This cycle can continue, and typically, school myopia stabilizes between -6.00D to -8.00D, although it can vary depending on the vertex distance (VD) and other factors.
Management Strategies for School Myopia
Controlling school myopia involves reducing the eye’s tendency to over-accommodate and preventing rapid progression. Here’s how we manage it effectively:
1. Plus Lens Support for Near Work
Providing slight plus-powered lenses (+ lenses) for near tasks can reduce the eye’s need to over-accommodate. This relaxes the ciliary muscles and slows myopia progression.
• For example, giving a child a +1.00D lens for reading can help balance accommodation and reduce eye strain.
2. Low-Dose Atropine Drops
Atropine eye drops (usually at low concentrations like 0.01%) are widely used to slow myopia progression by relaxing the eye’s focusing mechanism.
• Atropine reduces the eye’s ability to over-accommodate, effectively “resting” the lens.
• This method is safe for long-term use in children and can significantly slow down the progression of myopia.
3. Increased Outdoor Activity
Studies have shown that spending more time outdoors can reduce the risk of developing myopia. Natural light exposure and long-distance focusing help relax the eye’s accommodative system.
• Encourage at least 2 hours of outdoor activity daily.
• Limit continuous near work by following the 20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds.
4. Orthokeratology (Ortho-K)
These are rigid gas-permeable contact lenses worn overnight to temporarily reshape the cornea.
• They provide clear vision during the day without lenses or glasses.
• Ortho-K has been shown to slow axial elongation in children, making it a valuable tool for managing school myopia.
5. Multifocal and Myopia Control Lenses
Specially designed multifocal soft contact lenses and defocus spectacle lenses (like the MiYOSMART lens) help reduce peripheral hyperopic defocus, which contributes to myopia progression.
Why Axial Myopia Management Is Different
It’s important to note that these methods are primarily effective for refractive (school) myopia. In axial myopia, where the eyeball’s structure is the issue, these strategies offer little benefit. Axial elongation requires more aggressive management, and surgical correction is often the only permanent solution once the eye stops growing.
Final Thoughts
Managing school myopia is about more than just prescribing glasses—it’s about understanding the underlying cause and preventing its progression. As optometrists, we need to educate parents and children about the importance of:
• Proper visual hygiene
• Outdoor activity
• Regular eye check-ups
• Early intervention with myopia control strategies
By combining corrective lenses with lifestyle changes and advanced treatments like atropine drops or Ortho-K lenses, we can effectively manage school myopia and protect children’s vision for the future.
Healthy vision today means a brighter tomorrow.
Written by an Optometrist Dedicated to Pediatric Eye Care and Myopia Management