Plenty of people – though maybe not President Donald Trump – heeded advised and donned eclipse glasses or other proactive eyewear to watch Monday’s Great American Eclipse. But if you happened to have spent a little too long looking up as the moon blocked the sun, when will you know if you’ve damaged your vision?
You may not know for a while.
Staring directly at an eclipse – or at the sun at any other time – can damage your vision. During normal daylight conditions, the eye’s iris contracts so that only a small amount of light passes through the lens and reaches the retina. During an eclipse, people turn their eyes to the sun for a longer period of time and that can cause damage.
If the cornea in the front part of the eye becomes sunburned, you can develop eye pain and light sensitivity, something known as solar keratitis. The sun’s brightness is enough that staring at it for even a short period of time it can produce enough light to damage individual retinal cells, a more serious condition known as solar retinopathy.
Depending on how long you looked at the sun and how badly your retinal cells were damaged, the spot will either fade away quickly or remain permanent. There is typically no immediate way to know if you’ve damaged your eyes because the retina has no pain receptors.
“Exposing your eyes to the sun without proper eye protection during a solar eclipse can cause “eclipse blindness” or retinal burns, also known as solar retinopathy,” PreventBliindness.org explains. “This exposure to the light can cause damage or even destroy cells in the retina (the back of the eye) that transmit what you see to the brain. This damage can be temporary or permanent and occurs with no pain. It can take a few hours to a few days after viewing the solar eclipse to realize the damage that has occurred.”
Symptoms of solar retinopathy can occur within hours of looking at the sun but can take as long as 12 hours to appear. In some cases, the damage won’t appear until up to 24 hours – or even up to 2 weeks – after exposure.
- Blurry vision
- A central blind spot in one or both eyes
- Increased sensitivity to light
- Distorted vision
- Changes in the way you see color, known as “chromatopsia”
If you experience discomfort or vision problems after watching the eclipse, visit your eye doctor.