All About Myopia: Causes, Symptoms, and Management

April 11, 2023
All About Myopia: Causes, Symptoms, and Management

Myopia also known as nearsightedness is a condition in which close objects can be seen clearly but distant objects appear blurry. It is one of the commonest disorders of the eyes affecting mainly children of growing age. Myopia is on the rise all around the world. A recent landmark publication has predicted that, by the year 2050 half of the world will be myopic or nearsighted.1

Following are the types of myopia2

  • Mild nearsightedness (generally less than 3 diopters of myopia) is also called low myopia.
  • Moderate nearsightedness or myopia is 3 to 6 diopters of myopia.
  • Severe nearsightedness (more than 6 diopters of myopia) is also called high myopia.

Myopia progresses in children as the age increases and stabilizes around an age of 20 years.2

Along with rise in number of cases of myopia there is evidence of a rise in severity of myopia as well. In high myopia a visual acuity of a person is far worse than the threshold for blindness (–3/6 in the better eye). It is estimated that 9.8% of global population will fall in this category of high myopia by the year 2050.3 The highest prevalence of myopia is observed in younger adults of urbanised East and Southeast Asian countries. 3

Risk factors for myopia - In recent studies, risk factors for myopia in school children were considered as low outdoor time and near work, dim light exposure, use of LED lamps for homework, low sleeping hours, reading distance less than 25 cm and living in an urban environment.4

Complications of myopia - High myopia is associated with an increased risk of developing sight-threatening conditions such as myopic macular degeneration, retinoschisis (condition in which retina divides into two or more layers), posterior staphyloma (backward outpouching of the eye), glaucoma retinal detachment, and cataract.1

A study conducted on school children of aged 6 – 8 years in 2021, during the COVID-19 pandemic has found potential increase in myopia incidence, significant decrease in outdoor time and increase in screen time among schoolchildren. The results of the study are warning to eye care professionals, policy makers, educators and parents, that collective efforts are needed to prevent childhood myopia—a potential public health crisis as a result of COVID-19. 5

Myopia is already one of the major causes of vision impairment and blindness, is projected to affect almost half of the world's population. Urgent action is required to be taken from governments, NGOs and researchers. Policy makers must recognise the risk of increasing myopia and ensure availability of appropriate detection and treatment. Myopia control is possible if myopia control strategies are adopted as soon as a child becomes myopic. Parents should also be encouraged to monitor the time their children spend on near devices and encourage time spent outdoors.1