Monday, December 5, 2011

Can you really go blind by staring at the Sun?

Let's start the week with a question. Can you really go blind by staring at the Sun?

Short answer: No.


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Sunrise captured in Penampang, Sabah.

Long answer (I thought you'd love this): Yes, but....

It's possible, but the hazard is often exaggerated. Even at midday, a normal eye will only let in enough light to heat the retina by about 4°C. You need at least 10°C to cause thermal damage. Looking at the Sun during an eclipse for more than a minute can cause damage, because your pupils are more dilated, but it doesn’t result in total blindness and isn’t usually permanent. If the Sun is within 10 minutes of setting below a sea-level horizon, the more dangerous short-wavelength light is absorbed by the atmosphere and it should be quite safe to look at the Sun.

Source: sciencefocus.com

4 comments:

Joanne Juend said...

beautiful sunrise! :)

de engineur said...

@Joanne Juend. Thanks a lot.

thomas said...

I would rather not look at it directly or even throught the viewfinder,only do that at sunrise at sunset.

de engineur said...

@thomas. There's also suggestion that looking at the sun through lens or binoculars is dangerous as glasses in these equipment concentrate rays and it could increase the risk of retina burn.

Coming back to what you said, I metered the shot by focusing on the mountain, re-compose by including the sun then fired away.