How can solar retinopathy result from looking at the Sun during an eclipse?

Looking directly at the Sun during a solar eclipse is dangerous because the Sun remains extremely bright even when partially obscured. As the environment darkens during an eclipse, your pupils dilate, allowing more light to enter the eye. This intense light can damage the retina, the light-sensitive tissue at the back of the eye.1

Because the retina lacks pain receptors, you will not feel the injury as it occurs; symptoms such as blurred vision, altered color vision, or central vision loss may not manifest until hours or days later. This condition is known as solar retinopathy.1

To view an eclipse safely, you should use eclipse glasses that meet the ISO 12312-2 standard or employ indirect viewing methods, such as pinhole projection. Never use ordinary sunglasses or unfiltered optical devices like telescopes or binoculars to look at the Sun.1