MYOPIA PREVALENCE IN ASIA
A row of Asian children with impaired vision, created by their eye doctors.
This is Asia today and the world tomorrow.
1) In Singapore, the vision of 421,116 males between the ages of 15 and 25 was examined. In 1974-84, 26.3% were myopic; in 1987-91, 43.3% were myopic. Both the prevalence and severity of myopia were higher as the level of education increased. The prevalence rate was 15.4% in males with no formal education and increased steadily through the education levels to reach 65.1% among the university graduates in 1987-91. The authors state that their findings confirm indications from other sources that the association between the prevalence and severity of myopia and education attainment is real (M.T. Tay, K.G. Au Eong, C.Y. Ng and M.K. Lim, "Myopia and Educational Attainment in 421,116 Young Singaporean Males," Ann Acad Med Singapore, 1992, Nov;21(6):785-91).
2) Regarding the prevalence of myopia in Asian countries, Lam and Goh (Lam, C.S. and Goh, W.S., "The incidence of refractive errors among schoolchildren in Hong Kong in relationship with the optical components", Clin. Exp. Optom., 74:97-103, 1991) found that in 383 school children from ages 6 to 17 years, the prevalence of myopia increased from 30% at ages 6-7 years, to 70% at ages 16-17 years.
3) Lam and Yap (Lam, C.S. and Yap, M. "Ocular dimensions and refraction in Chinese Orientals", Proc. Int. Soc. Eye Res., 6:121, 1990) found that in a group of optometry students at The Hong Kong Polytechnic University, the prevalence of myopia was 75% in females and 69% in males.
4) Goh and Lam (Goh, W.S. and Lam, C.S., "Changes in refractive trends and optical components of Hong Kong Chinese aged 19-39 years," Ophthal. Physiol. Opt., 14:378-382, 1994) found that in 2000 first-year students at the University of Hong Kong, the prevalence of myopia was 87.5%.
5) Lin et al (Lin, L.-K, Chen, C.J., Hung, P.T., and Ko, L.S., "National- wide survey of myopia among schoolchildren in Taiwan, Acta Ophthalmol.", 185:29-33, 1988) found that in a national survey of children in Taiwan, the prevalence of myopia was over 70%.
6) Lin et al (Lin, L.K., Shih, Y.F., Lee, Y.C., Hung, P.T., and Hou, P.K., " Changes in ocular refraction and its components among medical students - a 5-year longitudinal study", Optom. Vis. Sci., 73:495-498, 1996) found that in a study of 345 National Taiwan University medical students, the myopia prevalence increased from 92.8% to 95.8%! over the five year period.
7) A recent study in Hong Kong showed what other studies have shown - wearing less than a full correction will slow the progress of the myopia. Children selected for the study were between the ages of 9 and 12. All were nearsighted, with 1.00 to 5.00 D of myopia. The children were separated into three groups. Each group was given a different type of eyeglasses to wear for the two-year period of the study.
The first group wore single vision lenses with a full correction; the second group wore progressive lenses with a +1.50 add; the third group wore progressive lenses with a +2.00 add. All children were examined at 6-month intervals to check the progression of their myopia. Sixty-eight children completed the study. As expected, more undercorrection meant slower myopia progression.
Single vision lenses: 1.23 D increase
Progressive lenses with +1.50 add: 0.76 D increase
Progressive lenses with +2.00 add: 0.66 D increase
Source: Leung JT, Brown B. Progression of myopia in Hong Kong Chinese schoolchildren is slowed by wearing progressive lenses. Optom Vis Sci 1999; 76:346, 354. Published 10/07/00.
8) Myopia Increases Among Children
By Liu Shao-hua
December 6, 2000
One of every five children in the first grade in Taiwan's elementary schools is myopic (nearsighted). The proportion of myopics in this group has increased from 12.1 percent in 1995 to 20.4 percent this year, according to the results of a survey released by the Department of Health yesterday.
The results also show that 60.7 percent of sixth graders in elementary schools, 80.7 percent of third graders in junior high schools, and 84.2 percent of third graders in senior high schools suffer from myopia. In addition, the number of seriously myopic children is also on the rise. The proportion of seriously myopic children among sixth graders in elementary schools has increased from 2 percent five years ago to 2.4 percent this year.
Serious myopia is defined as exceeding 600 degrees (6 diopters). Anything over 25 degrees (0.25 diopters) is myopia. Normal eyesight is zero degrees.
"We appeal for reductions to children's work load in schools and the amelioration of visual environments in daily life," said Chen Tzay-jinn, director-general of the health promotion bureau, under the health department.
The survey was conducted by the department, in cooperation with National Taiwan University and its hospital, and involved a sample of 12,000 students from four million students between the ages of 7 and 18 nationwide. Myopia has been on the increase in Taiwan ever since the first myopia survey in 1983. The department manages the survey every four or five years.
The growth of nearsightedness among young children is thought to result from learning to read very young and using computers very young, Chen pointed out.
Last year, the department and the Ministry of Education delivered official documents to kindergartens nationwide demanding that children not be taught to read or use computers too early. "But many teachers and parents protested against this appeal," said the department officials. "They questioned exactly what they were permitted to teach if reading was not allowed."
"We do hope that parents and teachers can heighten their awareness of myopia and understand that early learning does not guarantee students' performance in the future, but it does bear a strong correlation to defects in vision," Chen said. The department also appealed for children under the age of 10 not to be taught how to use computers.
Senior high school students suffer the highest rates of nearsightedness, at over 84 percent. "It reached a plateau five years ago and has not changed this year. But their myopia has become more serious," Chen said. According to the survey, 20 percent of third graders in senior high schools are seriously nearsighted.
Many people thought operations could cure myopia. "But the superficial improvement of vision does not better the health of the eye. More importantly, it might reduce people's awareness of other problems associated with nearsightedness, apart from visual ones," said Lin Lung-kuang, ophthalmology professor at National Taiwan University. "Myopia cannot be cured. We have to prevent children from becoming nearsighted. Don't let them use their vision too early," Lin urged.
Because of the public's lack of awareness of myopia, the department estimated its prevalence would continue to grow. "Singapore resembles Taiwan in many respects and the extent of its myopia problem might serve as a warning for us," Chen said.
In Singapore, 60% of the children are myopic by age 12; 80% are myopic by age 18; 79% of adults are myopic. And over 90% of university graduates are myopic. And eye doctors around the world continue to say this is inherited. Singapore is the first country in the world to take a timid step forward and publicly state that myopia is caused by prolonged close work. But so far, in order not to upset the optical industry, they only pay lip service to the idea. They do not mention the use of plus lenses and they do not mention the dangers of minus lenses. The only pitiful advice they offer is to look up from time to time as you read, push the book away, and spend more time outdoors. See their website at Singapore National Eye Centre. Below is another graphic example of mass myopia in Asia.