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Is it safe to Look at clouds with binoculars during the day? (1 Viewer)

JOC1

Member
United States
Hello everyone, I wanted to see if anybody knew if it was safe to look at clouds during the day with binoculars. Usually a partly cloud day with the sun out, you get to see some great detail in the clouds, But I worry sometimes if it could be harmful to your eyes if they are too bright. (Note: the sun is not behind that cloud or even next to it. )

This issue sometimes pops up when looking at the moon. It can be extremely bright but everyone says it’s safe to view.

So just wanted to see if this was also the case with bright clouds .

thanks!
 
Last edited:

Binastro

Well-known member
Individuals vary in their tolerance to bright light, either to eyes or skin.

One individual may have different tolerances to light at different times.

Medication, such as antibiotics and several other common treatments can greatly increase susceptibility to light.

Migraine sufferers may not tolerate bright light well.

When exiting a dark room when dark adapted, it may take a considerable time to adjust to bright sunshine.

Bright sunshine can affect dark adaption for more than 24 hours.

Viewing the full Moon at night can be uncomfortable
The albedo of a half Moon is much less than a full Moon.
If a full Moon is uncomfortable one can use a 2x or 4x neutral density filter.

The Sun should never be viewed with unaided eyes and certainly not with optical aid.
The Sun is at least half a million times brighter than full Moon.

The visual magnitude of the full Moon has been overestimated in the past.
It only reaches brightest when at the zenith exactly at full Moon.
Most full Moons are less than half this brightness.

If viewing clouds well away from the Sun feels uncomfortable, don't continue.

Dangers when the Sun is out and bright should be considered.

Regards,
B.
 

CharleyBird

Well-known member
England
Bit of history here:
I was reading recently about Thomas Harriot, the 'tacit genius' who seems to have been first among astronomers for so many things, but his 'great reservednesse' meant he never published his observations and methods. He relied on misty mornings beside the river at Syon House to look through his telescope directly at the sun !!!
In March 1612, his observation notes record, "At 12h all the sky being cleare and the Sonne I saw the great spot....My sight was after dim for an houre"


Sounds like he was extremely lucky not to suffer permanent eye damage.
 

MiddleRiver

Well-known member
United States
The question was a valid one and 'common sense' alone might not suffice. I have wondered whether extended bino use would aggravate UV eye damage and thus possibly accelerate cataracts etc. since clear glass blocks UV-B but not UV-A.
 

Maljunulo

Well-known member
Isn’t it well known, and easily seen by looking at transmission curves that the optical train of a binocular is practically opaque to ultraviolet light?
 

Tired

Well-known member
United States
Viewing clouds that aren't immediately next to the sun, with binoculars or not, should be safe. But it can be quite bright and uncomfortable on the eyes, so it's a reasonable question. Different comfort levels apply, but there are plenty of things that are unpleasant on the eyes without being dangerous. Otherwise certain shades of bright pink might have to be sold in restricted amounts only.
 

MiddleRiver

Well-known member
United States
Isn’t it well known, and easily seen by looking at transmission curves that the optical train of a binocular is practically opaque to ultraviolet light?
 

Binastro

Well-known member
Damage to the eye also occurs with near blue visible light.

It is the total exposure to light over many years that accelerates eye damage.
Although very high intensity light will cause sudden damage.

Eye problems probably are also just age related.

Some opticians suggest wearing good sunglasses even when cloudy to reduce age related eye problems.

People live considerably longer now than say one or two hundred years ago, so all sorts of age related health issues arise.
Modern medicine helps a lot, but eyes are sensitive.

Regards,
B.
 

Maljunulo

Well-known member
Perhaps I misunderstood the question, but I assumed that the question was asking if UV protection was needed specifically when looking through a binocular, irrespective of other times or other circumstances.

I stand by my answer.
 

Patudo

Well-known member
I spend a lot of time searching clouds for raptors, but in late spring/summer brightly lit clouds can be too bright to look at, so I don't. Outstanding brightness is normally a good thing in binoculars, but for situations like this a binocular can be too bright - and a slight colour cast, normally not considered desirable, can help take the edge off the very harshest brightness.

Bit of history here:
I was reading recently about Thomas Harriot, the 'tacit genius' who seems to have been first among astronomers for so many things, but his 'great reservednesse' meant he never published his observations and methods. He relied on misty mornings beside the river at Syon House to look through his telescope directly at the sun !!!
In March 1612, his observation notes record, "At 12h all the sky being cleare and the Sonne I saw the great spot....My sight was after dim for an houre"

Sounds like he was extremely lucky not to suffer permanent eye damage.

If he did that on anything like a regular basis I'll bet his eyes did suffer permanent damage!!!
 

Binastro

Well-known member
Newton was reported as having eye damage from solar observing with his very small telescope.

Unfortunately several astronomers have had permanent eye damage.
My friend had instant permanent damage in one eye from a one inch telescope plus several sunglass lenses in front. At age 11.

Any colour light can damage eyes if the intensity is high enough.

Green, red or infra red lasers can damage eyes if bright enough.
Pilots have had to give up flying from deliberate attacks.

Regards,
B.
 

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