Myopia is not just an inconvenience to be corrected by glasses or contact lenses. Higher rates of myopia can give rise to more serious pathologies, such as retinal detachment, and the trend is towards higher and higher degrees of myopia.
Over the past couple of generations, there has been a worldwide increase in the incidence and the severity of myopia (short-sightedness). In the Far East over 80% of children are now short-sighted. In the USA the rate has jumped from 25% to over 40% in a generation. These figures are repeated around the world. Because of the rapidity of the change, it cannot be an inherited trait. It is due to environmental factors. Today’s children are spending more time than their parents and grandparents in front of computers and in artificial lighting and less time outdoors in natural daylight.
Because of the seriousness of the issue, studies are ongoing to establish the mechanisms responsible for this phenomenon, and into possible ways of controlling its progression.
While no definitive cure has been found to date, some lifestyle changes can make a difference. Spending two hours each day outdoors helps, for example.
Certain contact lens modalities have been shown to slow the progression of myopia. Currently the most successful type is Ortho-Keratology (Ortho-K). An Ortho-K lens is worn overnight and removed in the morning. While sleeping, the cornea is moulded by the lens to allow the patient to see clearly throughout the following day. The peculiar shape of the image that this process forms appears to deter the eye from growing excessively, and slows the progression of the myopia. Work is now underway to develop a soft lens option that will give a similarly shaped image shell.