Myopia is an error of refraction of the eyes, due to eyeball being too long, causing people suffering from it to see distant objects poorly. It is commonly called nearsightedness. People suffering from this condition must hold objects close to their eyes, and the eyes must be made to converge by increased activity of the internal rectus muscles. If these muscles are inadequate, strabismus may develop. Myopia often occurs in students doing copious amounts of reading and writing and also among workers in various fields which require close attention to detail.
There has been e dramatic increase in myopia in developed countries over the past 200 years. It now affects 30 per cent of people of European descent.
There is some evidence that young children who sleep with night lights on may develop a higher incidence of myopia. Also that diets high in refined starches, such as breads and cereals, or sugar, increase insulin levels, which affect the development of the eyeball making it abnormally long and causing short-sightedness.