Screen-Work is Blinding Us: How We Turn the Tide on Myopia
There is little doubt at this point in our evolution that time spent with a computer is time spent training the eyes for a single, narrowly applicable, focal-posture. However, though speaking of evolution, this is not a genetic development; it is an adaption brought on by dramatic environmental transformations.
Within native Alaskan Inuit populations, the introduction of western classrooms and screens multiplied the incidence of myopia by nearly 10-fold in a single generation. Tech-heavy countries in East Asia are now reporting as high as a 96% myopia rate among teenagers. The number of cases doubled in the U.S. between ’72 and 2004. It is not a matter of electronics, either, since excessive time spent with books achieves similar pathology. The fact is, we spend more and more time working on detailed visual tasks at short distances and from a younger and younger age.
The myopic pandemic is costing us not only our eye-sight but also in dollars, estimated at $328 billion per year in medical care. Myopia increases the likelihood of experiencing much worse ophthalmic disorders later in life. Eye-strain from screen work is also costing companies in productivity. Visual impairment resulting of such work becomes apparent even in the short term after only 3 hours of computer work. But it does not appear that it is the screens themselves — it is more and more apparent that it is rather, our lifelong uninterrupted patterns of use.
Certainly high energy light can damage the cells of the eye, but not the light of phones or screens. A recent Nature study showed that screen-light is too low intensity to directly damage cells of the eye. The visual impairments associated with screen work cannot be blamed on the blue wavelength of the light either since sunlight is beneficial and contains plenty of blue. The absence of certain natural frequencies like near-IR could potentially lower the metabolic activity of cells, perhaps even in the retina, but there is no evidence that this contributes to progression of ophthalmic disease or degeneration. On screen apps are even being designed to fight myopia and show some promise. In other words, we are probably not dealing with a cellular pathology due to electromagnetic phenomena in the widespread tech-associated myopia, but rather a biomechanical, developmental etiology. Human behavior has changed and the human eye is being reshaped to meet the demand.
Can We Heal from Myopia?
A healthy eyeball focuses on distant objects by changing the shape of the corneal lens. There are competing theories for the mechanism by which this is accomplished, however, it is widely accepted that sight at a distance involves the relaxing of ciliary muscles. When we focus on something up close, like a screen or cellphone, we have to contract those muscles in order to accommodate the lens deformation with thickness and convexity. Perhaps myopia can result from a sort of learned tension in the cilial muscles? And if this were the case, we should be able to retrain a more relaxed focus, right?
There is some evidence that we are, in fact, able to improve certain aspects of our vision through training. Certain popular program like the Bates method aim to strengthen extra-ocular muscles but have not been substantiated under strict controlled investigation. Ayurvedic or other corrective practices aimed at relaxing the cilial muscles may have a mild beneficial effect on perceived eyesight, though objective measures of myopia are largely unaffected. Similarly, biofeedback mechanisms that train visual acuity improve sense of well-being but not myopia. In addition to the apps mentioned there are several computer-based training modules that have shown some minimal efficacy. Indeed there may be complex feedback mechanisms at play between the mind and eyes, that circles in on visual acuity, but the ability to retrain a myopic eye seems, for the moment, highly limited.
Technologies like peripheral defocus glasses have made some headlines, but their long-term effects seem marginal and temporary at best. When contact lenses were first developed, it was noted that the stiff implants had the unintended side-effect of flattening the cornea and decreasing myopia. A large study in the 1980s found that the technology that sprung up around this corrective phenomenon, called orthokeratology, was unfortunately only transiently effective. Orthokeratology can slow down the disorder but not prevent or repair it. Similarly, drugs which affect relaxation of the cilial muscles have shown more efficacy than any of the other technologies, but their off-target effects often prove too cumbersome to make such pharmacological intervention useful. Again, lens-control therapies do not cure the problem but merely salve it momentarily. This may be because lens control is only one minor piece of the myopia pathology.
The Biomechanical Development of the Eye
See, the principle structural change associated with myopia is axial lengthening of the eye. In other words, myopia may reflect that the entire eye adapts for the form required by its duties. Since the structural portion of the eye, the sclera, has a rubber-like Poisson ratio, once eyes grow into a shape they are going to retain it. Neither exercising one’s eyeballs for hours and hours a day nor relaxing them with drugs or prostheses is capable of reshaping an incompressible material. Perhaps this is why our best hope for fighting the myopia pandemic is in nurturing the healthy growth of our children’s eyes.
Restraining children from excessive near-field work is essential, in general, though there may be means of combatting the progress of myopia without outright abstinence from computers. Outdoor play, for instance, seems to be more important than mere hours spent with books or screens. The WHO recommends 2-3 hours a day of outdoor play. This has proved effective in early test countries, including Singapore, India, and China. Fancier, more competitive schools are also more likely to entrain myopia, perhaps because those students are less likely to have time for outdoor activities. Perhaps it would be wise for them to consider natural lighting solutions for their classrooms and pass-throughs.
It seems that the earlier in our children’s lives we address the pathology, the better. If infants below the age of 2 can avoid screens altogether, it seems they have the best shot of healthy vision in the future. Unfortunately, at present, 90% of parents report that their infants in these age range spend time with screen-based media. We can start by adopting strict containment policies in our own families for these technologies. An easy place to start is restricting pre-bed-time use of devices, which will also improve sleep quality and associated cognition. A good rule of thumb is if you can accomplish a particular teaching/play activity with your child without involving highly-detailed near field work, you’ll be doing them invaluable service. If you can move the activity outdoors, In natural light, whether sunny or overcast, you’re multiplying your child’s returns.
The lives of humans on this planet have changed wildly in the past 200 years. In many ways, we are progressively tempering widespread suffering and we have the demonstrated capacity to change the course of previously immutable paradigms. Humans are predominantly visual creatures. Considering our newfound abilities to combat extreme poverty, move toward peaceable co-existence, and manipulate our genetics, it shouldn’t be so difficult to take responsibility for the eyesight of our children moving forward. Strict provisions for outdoor play throughout development, routine screen recesses in school, and outright exclusion from infant usage could almost certainly curb myopia to pre-industrial levels in a single generation. If the COVID-19 pandemic taught us anything, acting early is the key to cutting losses in a public health crisis.
