Poor eyesight hit a record high in elementary, junior and senior high schools in fiscal 2016 as children spent more time reading from gadget screens, but tooth decay and obesity continued to drop, the government's annual health survey says.

The education ministry reckons changing lifestyle habits are behind the trends.

Students who earned a healthy eyesight rating of 1.0 on the Japanese system came to just 31.4 percent in elementary school, 54.6 percent in junior high and nearly 66 percent in high school, the annual survey showed Thursday.