SHANGHAI, June 6 (Xinhua) -- The overall myopia rate among children and teenagers in Shanghai is about 56.6 percent, with the rate among senior high school students as high as 84.4 percent, the municipal health authorities said Thursday.

The myopia rate of the city's children and teenagers is three percentage points higher than the national average.

About 8.4 percent of six-year-olds are nearsighted, and the rate jumps to 35.5 percent among primary students, and 77.2 percent for middle school students.

The health commission also said 23.4 percent of senior year high school students suffered high myopia.

To combat myopia, the local government has introduced various measures such as increasing the time for outdoor activities, renovation of classroom lighting, readjusting desks and chairs in schools, and better access to eyesight correction.