Contact lenses for myopia control
Myopia has become the most common refractive error around the world. In the Western world, 40% of the young population and in some Asian countries are even reaching more than 80%. Myopia is not just an unfocused problem. In myopia, there is more risk of cataracts, glaucoma, or retinal problems.
It is not surprising, then, that there is much research on how to avoid its appearance or decrease its amount. Originally, there are genetic factors, but also environmental factors. Genetics is relatively stable. Life habits have changed a lot in recent years. There is much more reading, more computer, tablet and mobile and more time indoors.
In recent years, the role of sunlight has been greatly enhanced. The longer children are outside, the less myopia may develop. Now it is believed that this has been the most important factor that has changed more in recent times.
But, as the life we carry is basically indoors, other ways have been sought. Atropine is a medication that instillates at very low doses has shown that it is very effective in avoiding the progression of myopia. Because its effects are not known in the long term and also, due to its side effects of blurred vision and photophobia, it has not been applied (only in research).
Also, it has been tried to graduate the glasses with a little less myopia, but is currently totally discouraged because it has been shown to be inoperative.
Normal contact lenses or lenses of the glasses focus the image exactly on the retina, in this way a clear image is seen. As the retina is not flat, but curved in its periphery, in this area the image is focused from behind. It has been discovered that the eyes use the peripheral blur to start the signal of increased myopia.
Some special soft contact lenses have been developed with a special design on the periphery to avoid this peripheral blur behind the retina. Semi-rigid contact lenses of ortho-k also manage to do the same, but modeling the cornea. Clinical studies show an average reduction in the increase in myopia
The peripheral blur behind the retina causes the initial signal to increase myopia
The peripheral blur in front of the retina does not start a myopic process