I Can't See the Blackboard Reading Answers

The eye condition known as myopia is called, in lay terms, near sightedness or short sightedness. It is the condition where the eyes cannot focus on objects at a distance because the eye has changed shape, becoming more oval and long. This results in long distance focus not falling on the retina at the back of the eye, but in front of it, causing distant objects to be out of focus. It is an idiopathic disease, meaning that the cause is unknown. The term myopia comes from the Ancient Greek meaning 'a man shutting his eyes" probably in reference to the regular squinting that occurs when a short sighted person is trying to focus on a distant object. People usually begin to suffer from myopia between the ages of 9 and 15 and it is often picked up at school as children squint at the blackboard

Vision is measured by how strong a lens needs to be to correct refractive disorders. The standard unit is a dioptre and for myopia the measurements are in negative figures, while for hyperopia and presbyopia (the inability to focus on near objects), the measurements are positive. Of sufferers, around 95 per cent have common myopia which is less than -5 dioptres, around 4 per cent have high myopia which is between -5 and -10 dioptres and less than one per cent have more than -10, which is called pathologic myopia. Someone with high myopia cannot focus on objects more than 30 cm away from their eyes.

The percentage of the population with myopia differs between populations around the world, with East Asian populations at the highest level. Between 70-90 per cent of young East Asians are myopic, and over 50 per cent of young Europeans and Americans India's level of myopia in young people measured 5.7 per cent in the 1970s but has now more than doubled to over 13 per cent and is rising. The most affected world group is teenage boys in South Korea with an astounding 96 per cent being myopic. African populations are less affected with a less than 10 per cent instance of myopia. Scientists estimate that currently about 30 per cent of the total all-ages population has common myopia and around 4 per cent of that figure with high level. This is a massive jump from 22 per cent and 2 per cent only twenty years ago, and if current trends continue, more than half the world population will be myopic by the year 2050. Historically, myopia was a relatively rare condition. Before 1700, though it can only be estimated, it is thought that near sighted people made up less than 5 per cent of the population. One effect of myopia is that it increases the ability to see extremely small objects close up, and medieval monks with myopia were prized for their abilities to create fine intricate detail on illuminated manuscripts. After 1700, interestingly around the time more people began reading, numbers rose significantly to literate populations having an estimated incidence of around 17 per cent.

People with a high myopic parent are more likely to be myopic, and many genetic variations have been found to have some effect with about 200 influential genes so far discovered. However, such a huge increase in the prevalence in nearsightedness over such a short period of time has led scientists to believe that there is more at play than mere genetics. Environmental and lifestyle factors seem to have a much more important role. There is a clear correlation between both spending time indoors and spending time with eyes focused on close objects when reading, working on is currently being done to discover why this is computers and using hand held devices. Research affecting people's eyes so much. Generally, higher urban rather than rural living is also a factor. This socio economic groups have a higher incidence and makes sense in terms of the indoor/outdoor effect, and cultures which place a higher importance on study and academic achievement tend to have the fastest growing incidences. Studies have found a correlation between 1Q and myopia, but it is unknown whether it is a causal relationship. Do people with high IQs naturally become myopic or is it caused by their behaviour? Perhaps people with a higher IQ tend to be more involved in academic pursuits, which due to their indoor nature, increases the chances of developing myopia. In any case, general population IQs have not risen to the same extent as the incidence of myopia.

There is much discussion and research around the epidemic of obesity in modern populations, but there is comparatively little research into myopia, which is an epidemic of even greater proportions. As it is becoming clear that it is probably environmentally driven due to our changing lifestyles, there may be some way to mitigate it. Perhaps this epidemic has been ignored because it is quite easily corrected, but myopia is not as harmless as it may seem, as it leads to greater incidences of cataract, glaucoma and macular degeneration in later life and uncorrected myopia is the second greatest cause of blindness. There are most likely a

billion people in the developing world with myopia who do not have access to optical correction, which can lead to problems with completing their education, be the cause of accidents and prevent people from working. The alarming Increase in the onset myopia needs to be addressed so that ways can be found to control and even possibly eliminate it.