The Science Behind Myopia (Nearsightedness)
Nearsightedness, medically termed “myopia,” is a refractive error in which distant objects appear blurry while close-up objects can be seen clearly. This condition occurs when the eye’s shape causes light rays to bend incorrectly, focusing images in front of the retina instead of directly on its surface.
Common causes of myopia include an elongated eyeball or an overly curved cornea. It can begin in childhood and might progress with age. Corrective lenses, such as glasses or contact lenses, and refractive surgery are common treatments for myopia.
The cornea, as seen in the diagram on the right, is a clear, dome-shaped structure that overlies the colored iris. Corneal tissue is clear, and closely resembles wet skin, and like skin tissue, it is very pliable.
The cornea functions as a protective layer that separates the eyes’ contents from the environment and its unique structural curvature are able to bend the light rays towards the back of the eye. It is responsible for most of the eyes’ corrective power and contributes to various conditions such as nearsightedness (myopia), farsightedness (hyperopia), and astigmatism.
Managing Myopia (Nearsightedness)
Myopia control is used to slow or stop the increase in the axial length of the eye (how long the eyeball is). Blurry vision will cause the eye to extend in axial length, and as the axial length increases, the level of myopia will get larger. Children and adults can be treated with Ortho-K because the principle of flattening the cornea is effective for both types of patients.
Myopia control is used to slow/stop the increase in axial length of the eye that occurs in growing children who suffer from the effects of increased nearsightedness each year (patients whose spectacle prescription continues to increase in power every year). Myopia control therapy can result in a lower prescription, so the patient won’t have to wear thick lenses, otherwise required, by the time they become a teenager.
One of the most exciting areas of research in Orthokeratology and Corneal Re-shaping (CR) has to do with the control of myopic progression. At the present time, it appears that CR can essentially stop the progression of myopia in a young, emerging myope (someone who experiences nearsightedness).
The use of CR lenses on a young myope is the best alternative for preventing the progression of myopia. Research indicates that it is better than Rigid Gas Permeable lenses (RGPs), bifocal therapy, progressive lens therapy, atropinizing drugs, vision therapy, and under-correcting myopia.
Signs You May Need Eye Glasses
- Blurred vision
- Difficulty seeing at night
- Trouble adjusting from dark to light
- Frequent headaches
- Difficulty with computer use
- Eye Strain or fatigue
- Seeing halos
- Double Vision
- Blurry vision such as nearsightedness or farsightedness
- A pressure or strain sensation around the eyes
Relationship Between Nearsightedness and Aging
Over recent decades, we’ve observed a global surge in the onset and progression of myopia, partly due to these changing visual habits.
As individuals transition into adulthood, myopia often stabilizes, offering a respite from its earlier progression. However, around the age of 40, many face another visual challenge: presbyopia. This age-related condition results in difficulty focusing on nearby objects, complicating vision for myopic individuals further. Those with high myopia need to be particularly vigilant.
Severe nearsightedness can elevate the risk of age-related eye conditions like retinal detachment, glaucoma, and macular degeneration. Therefore, irrespective of age, routine eye examinations are essential for myopic individuals to ensure optimal eye health and timely interventions.