Researchers have discovered new genetic risk factors, which work together with environmental factors, can lead to myopia, Germany's Johannes Gutenberg University Mainz said in a press release on Thursday.

An international group of researchers, including scientists involved in the Gutenberg Health Study of the University Medical Center of Johannes Gutenberg University Mainz (JGU), has uncovered nine new genetic risk factors, which work together with education-related behavior as the most important environmental factor, to generate the disorder, according to the press release.

Myopia, also known as short-sightedness or near-sightedness, is the most common disorder affecting the eyesight.

The results have recently been published in the scientific journal Nature Communications.

It is known from previous studies of twins and families that the risk of acquiring short-sightedness is determined to a large extent by heredity. However, the myopia-causing genes that had been previously identified do not alone sufficiently explain the extent to which the condition is inherited.

In addition to the genetic causes of myopia, there are also environmental factors, the most significant of which are education-related behavior patterns.

"We know from the Gutenberg Health Study conducted at Mainz that the number of years of education increases the risk of developing myopia," said Norbert Pfeiffer, Director of the Department of Ophthalmology at the Mainz University Medical Center.

There has been a massive rise in the prevalence of short-sightedness across the globe in recent decades and this upwards trend is continuing. Particularly in southeast Asia, the incidence of myopia in school children has increased notably over the last decades, which is likely due to an improvement in educational attainment,according to the study.