Myopia: is the nature‐nurture debate finally over?

Abstract

In the nineteenth century, the prevalence of myopia began to rise, and Cohn stressed the role of education. Later, based on twin studies, Sorsby argued that refraction was almost totally genetically determined. This became the dominant view. However, rapid increases in the prevalence of myopia were then reported, especially in East and Southeast Asia, where the prevalence of myopia in children completing secondary school is now 80-90 per cent, with around 20 per cent highly myopic, and at risk of ocular pathology. It is not possible to explain these rapid changes genetically, since gene pools cannot change that fast. Nevertheless, there are at least 200 genetic forms of myopia, but these account for myopia in only a low percentage of the population. Genome-wide association studies have identified over 150 single-nucleotide polymorphisms (SNPs) associated with myopia, but they account for < 10 per cent of the variation in refraction. In contrast, twin studies have given consistently high heritability estimates for myopia. The high twin study heritability may be explained by the limited environmental variation within twin pairs, combined with basic assumptions made in twin studies. The SNP-heritability approach suggests that 25-35 per cent of the variation may be accounted for by hundreds or even thousands of SNPs. The apparent conflicts in the literature can be explained by the aetiological heterogeneity of myopia, and the fact that estimates of heritability are population-specific. It has been proposed that environmental variation is more relevant to variations between populations; however, the current differences between populations are due to changes within populations, driven by educational pressures, and limited time spent outdoors. Ethnic differences in myopia and the effects of parental myopia now seem more likely to be explained by environmental influences. Genetic studies have not yet defined molecular pathways and preventive interventions, and the predictive power of current genetic data is limited.

The pitfalls of the traditional office ergonomics model in the current mobile work environment: Is visual ergonomics health literacy the remedy?

“…One issue which has recently captured attention in the scientific literature is a possible link between myopia and sunlight exposure. For many years there has been debate whether myopia has a genetic basis or is the result of environmental exposures such as performing close work [42]. High proportions of myopia have been linked to education levels [42] with associated blame on using digital devices.…”

“…For many years there has been debate whether myopia has a genetic basis or is the result of environmental exposures such as performing close work [42]. High proportions of myopia have been linked to education levels [42] with associated blame on using digital devices. Emerging evidence indicates that childhood myopia can be slowed by spending time outside in daylight [43] and there is conjecture that increasing the amount of daylight through school windows may reduce the risk [44].…”

Debunking a myopic view of nature versus nurture

“…The thorough scientific appraisal by Morgan and Rose of the history and interpretations of investigations into the genetic and environmental risk factors for myopias, and in particular for school myopia, could not be more timely given the recent publication by Plomin which is receiving much interest in the press. The insights of their paper apply far more broadly than to optometry alone.…”

“…The example of myopia is highly illustrative . Another example would be height, the trait used by Fisher to demonstrate his methods which he and others since have found to be highly ‘heritable’, in the sense that twin and other family correlations are consistent with a very large proportion of cross‐sectional variation being explained, statistically, by the germline constitution of people.…”

Modern optical methods of peripheral defocus correction

“…Эпидемиологические исследования показывают, что миопия имеет большее распространение в городах среди пользователей гаджетов (компьютеров), студентов вузов и у людей с высоким уровнем образования [5][6][7]. Современные теории патогенеза миопии предполагают, что не только наследственность играет решающую роль в развитии и прогрессировании миопии, но и факторы окружающей среды (интенсивная работа на близком расстоянии, сниженная физическая активность, особенно на открытом воздухе, и некоторые другие) [7,8]. Эти факторы реализуются посредством механизма зрительной обратной связи.…”