Myopia, also known as nearsightedness, refers to someone who sees things more clearly up close rather than in the distance. There are at least three forms of myopia.
Type I Myopia – present at birth (or soon after) in one or both eyes. This tends to be a more severe form of myopia and does not seem to be influenced by how one uses their eyes.
Type II Myopia – acquired or functional myopia. This type is usually heredity if it develops at a young age but it is affected by environmental influences. The progression of type II myopia can be influenced by extended periods of reading and screen time. The demands of engaging in more near work activities causes the focusing mechanisms of the eyes to shift inward. This type of functional myopia typically develops gradually, starting out as blur when shifting focus from near to far then becoming a constant blur for distance.
Given the increasing use of technology and handheld devices, our world and activities have shifted to being much more near focused. So it is no wonder we continue to see an increasing rate of patients being diagnosed with myopia. The Multi-Ethnic Pediatric Eye Disease Study (MEPEDS) conducted from 2003-2011 found that the prevalence of childhood myopia among American children has more than doubled over the last 50 years. This study was conducted by researchers and clinicians from the USC Eye Institute at Keck Medicine at USC in collaboration with the National Institutes of Health (NIH) and it is the largest pediatric eye study consisting of more than 9,000 Los Angeles area children age 6 months to 6 years.
Type III Myopia – this type is rare and is associated with other conditions such as diabetes. It often results from swelling of ocular features such as the cornea or lens.
What To Do About It?
Prescribing lenses to sharpen distance vision only treats the symptoms. To address underlying causes, developmental lenses that incorporate prism, bifocal, or progressive addition lenses (PALs) may be prescribed. Your optometrist might also recommend orthokeratology to slow the progression by temporarily reshaping the cornea through the application of rigid contact lenses. Also, patient education from a developmental optometrist on visual hygiene can be beneficial for targeting more of the underlying habits that contribute to the progression of functional myopia.
While functional myopia sounds like a common vision condition that can be well managed, its severity and impact on one’s life can vary depending upon the treatment sought and how early on it is addressed. With all of these various options to consider in treating the causes and symptoms, it is essential to see a developmental optometrist for a comprehensive vision evaluation. This way you can feel comfortable making a decision on which type of treatment will best fit your needs.