There are around 2.6 billion people with shortsightedness or myopia, this number is predicted to rise to around 4.9 billion by 2050. Myopia development is now understood to result from a complex interaction between visual and environmental conditions as well as genetic factors that control eye growth. Having one parent with myopia there is a 1 in 3 chance of a child becoming myopic. If both parents have myopia, then there is a 1 in 2 chance of the child developing myopia. Although genetics play a role in the development of myopia, research shows that our genes alone are not responsible for the recent increase in myopia within the population. Environmental factors, play a key role in preventing the onset of myopia. For example, the chance of developing myopia is reduced by 50% with 90 minutes of daily outdoor activity. Another environmental factor is the amount of near work. Time spent performing near activities and years of education, is related to a higher risk for myopia. Children should be encouraged to read on their lap at least 30cm away and not to read for longer than 45 minutes at a time. This time also includes the use of digital devices which according to recent studies is more than 3 hours a day for mobile devices. There are also eye related factors that have been found to be related to the onset of myopia. In general, if your child has only a small degree of hyperopia, or longsightedness, at the age of 6, then there is a greater risk of developing myopia. New technology to measure the length of the eye can also be used to predict the onset of myopia. The length of the eye, for a given age, can be compared to growth curves in order to predict the level of myopia in the future. Fortunately, your eye-care professional can assess myopia risk factors and measure axial length as part of your myopia management consultation. In general, children should at the very least undergo annual examinations, with a least one cycloplegic examination where drops are used to relax the eyes' focus.