Ultraviolet rays are part of the electromagnetic spectrum with wavelengths ranging from 10 to 400 nanometers, which are invisible to the human eye, but excessive exposure can damage the eyes. The German Association for Better Vision warns that even on cloudy summer days, people should not forget to protect their sensitive eyes, as some UV rays can still penetrate the clouds and reach the ground. Prolonged exposure to these rays may cause certain harm to the eyes.
The association also notes that reflected light from water surfaces means those who spend extended periods near water should be especially cautious about eye protection. If the eyes are overexposed to UV rays, symptoms such as redness, tearing, and eye muscle tension may occur. In such cases, people should reduce their time in the sun and, if necessary, wear sunglasses with UV protection.
In addition to water surfaces and sandy beaches, the glossy paper used in newspapers and books can also reflect light and harm the eyes, so children and those with cataracts should be particularly careful.