Infrared camera- damage to eyes.?

[jimbouk]

Just wondering if anyone knows if the infrared light from CCTV cameras can harm young children's eyes.?

No I'm not strange control freak, but I do have a CCTV system at home with camera in my toddlers rooms, fantastic way to see what they are upto , but no substitute to actually being there or physically checking on them.

They have night vision on them, just wanted to check the red light they emit is not going to do them any harm,

[DKL]

I haven't read all of this but Janet's stuff is pretty good usually.
http://www.optometry.co.uk/uploads/articles/33aa07...

Edited by DKL on Wednesday 11th January 21:59

[jimbouk]

DKL

Many thanks, good article, think I understand some of it;)

Think I will use the cameras in moderation rather than all night.

[Mr GrimNasty]

Don't be daft - the intensity from your CCTV night vision is far less than in natural light, and many orders less than the industrial sources that cause cataracts - they're talking about sources that are intense enough to be physically uncomfortable/painful to be near!

[mrmr96]

Mr GrimNasty said:

Don't be daft - the intensity from your CCTV night vision is far less than in natural light, and many orders less than the industrial sources that cause cataracts - they're talking about sources that are intense enough to be physically uncomfortable/painful to be near!

Yes it's less powerful but the problem is that because human eyes are not sensitive to IR light the pupils will stay fully dilated in the dark so more light will enter as a %. Does that make sense?

[Mr GrimNasty]

mrmr96 said:

Yes it's less powerful but the problem is that because human eyes are not sensitive to IR light the pupils will stay fully dilated in the dark so more light will enter as a %. Does that make sense?

Don't be ridiculous, the luminosity of the light is so low it will be of no consequence whatsoever, even if you strapped the LEDs to your eyeball and stared into them for 100 years 24x7. Unbelievable level of ignorance!

[mrmr96]

Mr GrimNasty said:

mrmr96 said:

Yes it's less powerful but the problem is that because human eyes are not sensitive to IR light the pupils will stay fully dilated in the dark so more light will enter as a %. Does that make sense?

Don't be ridiculous, the luminosity of the light is so low it will be of no consequence whatsoever, even if you strapped the LEDs to your eyeball and stared into them for 100 years 24x7. Unbelievable level of ignorance!

There's nothing rediculous in what I wrote, but there certainly is in your interpretation.

I didn't say that there would be damage. What I said was that it was basically a valid question to ask because human eyes don't contract when you shine IR light in them. It's one of the reasons why you have to be so careful working with IR lasers because at that frequency the eye won't react so there's no contraction of the pupil, blink or flinch reaction. (Similar problem to using lasers in night clubs etc, becuase clubbers who are on drugs will have a slower pupil contraction response, so they wouldn't blink/react in the same way as somone who's sobre, so the safety levels in terms of intensity and divergence of the beam are lower in this kind of environment.)

[trashbat]

mrmr96 said:

because human eyes are not sensitive to IR light

mrmr96 said:

the pupils will stay fully dilated in the dark

mrmr96 said:

Does that make sense?

No.

[mrmr96]

trashbat said:

mrmr96 said:

because human eyes are not sensitive to IR light

mrmr96 said:

the pupils will stay fully dilated in the dark

mrmr96 said:

Does that make sense?

No.

Why not?

[trashbat]

mrmr96 said:

Why not?

Because it hasn't effected a change to pupil dilation any more than me taking my trousers off would. I'm being facetious - I know what you mean. The fact is that compared to IR from the Sun (which remember you won't react to), or a powerful laser, it's going to be negligible.

http://www.rainbowcctv.com/ir/eye_safety.html

If you replace the sensor filter on an SLR camera with one that only allows infrared, you can take photos at normal speed - i.e. to take an IR-illuminated photo, you need a similar amount of IR light as you would have needed visible light. If you turn up the gain, as night vision cameras do, this is very little indeed.

[mrmr96]

trashbat said:

mrmr96 said:

Why not?

Because it hasn't effected a change to pupil dilation any more than me taking my trousers off would. I'm being facetious - I know what you mean. The fact is that compared to IR from the Sun (which remember you won't react to), or a powerful laser, it's going to be negligible.

http://www.rainbowcctv.com/ir/eye_safety.html

If you replace the sensor filter on an SLR camera with one that only allows infrared, you can take photos at normal speed - i.e. to take an IR-illuminated photo, you need a similar amount of IR light as you would have needed visible light. If you turn up the gain, as night vision cameras do, this is very little indeed.

From your link:

link said:

Bright natural light which contains infrared causes the eye to blink, the iris to contract and the viewer to look away. These normal defense mechanisms do not happen when the visible part of the light has been removed.

I didn't say anything about intensity, this ^ was the point I was making.