Television

Sitting too close to the TV

Some television sets sold before about 1968 emitted excessive X-rays, which helped create the warning that sitting close would damage your eyes. That engineering problem was eliminated; ordinary modern sets do not give off harmful rays at the viewer.

Sitting very close can cause temporary eye fatigue, which is why some eye doctors once suggested a distance of at least five feet. A few animal studies have explored whether sustained near-focus contributes to myopia, but there is little evidence that normal television viewing permanently damages otherwise healthy eyes.

Television and childhood obesity

A study involving researchers from Johns Hopkins University School of Medicine, the CDC, and the National Institutes of Health found that children’s weight tended to rise with hours of television viewed. Watching is sedentary, it displaces active play, it often comes with high-calorie snacks, and food advertising can encourage more eating.

The survey found that about 26% of U.S. children watched four or more hours per day and that only 20% took part in vigorous activity more than twice per week. Health guidance at the time recommended at least three periods of strenuous exercise per week.

Television was already the leading leisure activity for many school-age children. The study’s authors estimated that an average high-school graduate could spend 15,000–18,000 hours watching television, compared with about 12,000 hours in school.

The same research reported that activity declined as girls moved from ages 11–13 into ages 14–16. It also found lower vigorous-activity rates and higher television viewing among Black and Mexican-American children than among white children in that sample; nearly 48% of Black children watched at least four hours per day.

The data showed correlation rather than a single cause. Family routine, neighborhood safety, access to recreation, income, diet, advertising exposure, and screen time can all interact.

Why the curve peaks in the middle

The calculator treats some television as ordinary leisure and a little shared culture. Watching seldom or often receives a small bonus; occasionally receives the most. Never watching may mean missing common reference points, while excessive viewing suggests that passive entertainment is taking too much time from work, exercise, relationships, or other interests.