Prevalence of myopia is reaching epidemic proportions. It is proposed to increase to 50% from its present 23% by 2050. The risk of myopia is three times higher when both parents are myopic than when none are. It is likely that genetic and environmental factors interact towards the development of myopia.
Myopia is caused by the increased axial length of the eyeball. Increased Dopamine release under high light conditions has been thought to reduce axial elongation. Studies have shown that outdoor activities have a protective effect on the onset and progression of myopia in school children. A Chinese study has shown reduced myopia incidence over next 3 years by the addition of 40 minutes of outdoor activity at school. However necessary precautions like wearing wide-brimmed caps and UV protective glasses should be used to block the harmful effects of UV rays. Studies show that early onset and progressive myopes have significantly greater eyeball lengthening following near work. Sustained reading at distances less than 30 cms may be more damaging than overall long hours spent.
Control and Early intervention: Drugs like low dose Atropine show great promise in myopia control. However, detailed counseling with parents for side effects is necessary.
Orthokeratology: Use of overnight rigid gas permeable lenses is another modality of treatment.
In conclusion, we are yet far away from identifying all causative factors of myopia. The three major recommendations at present are-
1) increased outdoor activity.
2)avoidance of near work.
3) use of low dose Atropine.