With an annular solar eclipse expected on May 21, the Japanese Ophthalmological Society and the Japan Ophthalmologists Association are calling on people not to observe the eclipse with the naked eye.
In a joint press conference Thursday, the organizations pointed out the risk of retinopathy, damage to the retinas that can cause reduced or distorted vision.
To safely enjoy the eclipse, they recommended wearing special viewing glasses and to stop observation if any discomfort is felt. A piece of black glass or a black plastic sheet used when writing in a notebook is not sufficient to block harmful rays, they said.
Prof. Tetsuro Oshika of Tsukuba University, who serves as secretary general of the JOS, called for special attention to children.
"Children's eyes are easily damaged. They need to observe the eclipse under the direction of teachers or parents," Oshiaka said.