Can the light at the bottom of an optical mouse damage your eyes?

Because I am using one as a christmas tree decoration and people look straight into it every day.

John Bachir

Posted 2010-12-15T06:10:32.833

Reputation: 1 169

Answers

Unless the mouse is labelled as a class 2 laser device, then it will not cause damage to your eyes. Most (possibly all) mice are either not lasers or class 1 laser devices, which are safe under all conditions, and do not require labelling.

If you want to know a lot more detail, there is a company called Avago which owns lots of patents in the this area. They have produced a detailed document covering aspects of safety with regard to optical and laser mice [PDF].

Colin Pickard

Posted 2010-12-15T06:10:32.833

Reputation: 6 774

1@ColinPickard Your link gives a "document not found". Please delete or fix it. – totymedli – 2014-10-12T17:17:41.207

Most mice aren't using laser devices (either class 1 or 2) but just regular leds. – jlliagre – 2010-12-15T10:39:51.697

Well, I did spend some time experimenting with this few years ago.

I noticed that after spending several minutes staring directly at mouse LED at close range (as in 1-2 cm), the way I perceive colors changes. It resets back to normal after few minutes of not staring into the mouse, and as far as I can see, there was no permanent damage.

AndrejaKo

Posted 2010-12-15T06:10:32.833

Reputation: 16 459

2I think you'll find that happens with any coloured light - even with the different colours of "white" light, like the 3500K orangeish light from an electric lightbulb compared with the 5400K bluish light from the sun. – stib – 2010-12-15T09:50:14.873

2Cool! I can see colors and hear the grass grow. And DEA can't say anything 'cause it is the LED in my mouse's belly. ;-) – Aki – 2010-12-15T09:50:19.657

3You (over)stimulate the receptors for a specific color in your eye. When you look e.g. at a grey/white object afterwards, they are desensitized for a while, and you only perceive the colors from the other receptors (don't quote me on that, it's been a while since I read about it), so you see the opposite color (like yellow/blue). Perception is a funny thing, try googling for Adelson's checker shadow illusion, or the Hermann grid illusion. – Daniel Beck – 2010-12-15T11:15:56.183

1One of the factors used in classifying visible wavelength lasers devices as type III (i.e. safe) is the understanding that the blink reflex will help to defend you. Interrupting that defense is a bad idea. – dmckee --- ex-moderator kitten – 2010-12-15T15:59:30.090

3Please do not look into the laser with your remaining good eye. ;) – Paused until further notice. – 2010-12-17T20:12:45.257

1@Dennis Williamson Too late! I already zapped both my eyes! :) – AndrejaKo – 2010-12-17T20:34:31.377

5"As far as I can see", good one :D ! – Bertvan – 2013-02-28T13:28:25.643

It will deplete the pigments in the cells of your retina where the light falls, but it doesn't contain enough energy to actually cause any lasting damage.

Ignacio Vazquez-Abrams

Posted 2010-12-15T06:10:32.833

Reputation: 100 516

Citation, please. – None – 2016-04-13T16:02:14.070

@JonofAllTrades: "When light hits photoreceptive pigments within the photoreceptor cell, the pigment changes shape. [...] [Retinal] exists in the 11-cis-retinal form when in the dark, and stimulation by light causes its structure to change to all-trans-retinal."

– Ignacio Vazquez-Abrams – 2016-04-13T17:16:53.917

This is actually a very useful response and explains lots of things when looking at light/sun. – Omar Abid – 2017-08-31T06:32:22.690

I don't think the LED is powerful enough anyway. You may get blurry eye for a few moments but you can get that just by looking at a bright light bulb for a duration. Your retina can get a little bit tired if staring in it for too long but this is all from the strong light. And it is not infra-red. Humans cannot see infra-red light. It is visible red which is higher in frequency.

Thariama

Posted 2010-12-15T06:10:32.833

Reputation: 762

No, unless you have a infrared laser led but I guess invisible beams are not the best christmas tree decoration ... ;-)

jlliagre

Posted 2010-12-15T06:10:32.833

Reputation: 12 469

Wavelength effect what kinds of damage a bright light can do, but all wavelengths can be dangerous. Intensity is the single most relevant metric. – dmckee --- ex-moderator kitten – 2010-12-15T15:58:48.453

I agree with that but you are missing my point. All laser mice I'm aware of are in the IR spectrum so there is no chance the question is about them. You unlikely use IR lights to decorate a christmas tree. – jlliagre – 2010-12-15T16:55:55.790