My KeySonic Laser Mouse came with a warning to not look into the laser because it can harm the eyes. However sometimes it just happens for one reason or another that I pick up the mouse and see the bottom of it. But I see nothing, there's no red light or anything. Is the laser invisible? Is it emitting when the mouse is picked up? That would mean that it's an invisible signal that hurts the eyes, which is somewhat scary...

My brother has a Logitech laser mouse, and it shuts off pretty quickly after you pick it up. This means you would basically have to press it onto your eye to get it to turn on / possibly burn anything. That is actually kind amusing to think about (pressing a mouse up against your eye to burn yourself with a laser).

Is it actually a laser mouse or just optical?

I think Dranith is right. My Logitech G5 also has such a warning, and it's pretty damn hard to see the actual laser, but it is there. I imagine the fact that it stops working after about a cm or so off the mouse mat means that it shuts off automatically. I can see a really faint red light if I hold the mouse a tiny distance off my hand, but that's about it, maybe it's just weak as hell.

I think it might actually shoot out at an angle [cautiously raises mouse to eye]

Umm, mice are supposed to shoot their lasers out at an angle, or else they couldn't detect movement. My mouse doesn't turn off when I pick it up, but the laser hurts, even when you see it out of the corner of your eye... speaking of lasers, why do mice use them? Does it really need the high-powered light to detect something as obvious as movement? Or do I not understand this correctly?

Quote: Original post by adam_ospeaking of lasers, why do mice use them? Does it really need the high-powered light to detect something as obvious as movement? Or do I not understand this correctly?

They are for higher resolution then a standard optical mouse. Whether they actually make a difference or if it's just hype I'm not sure. I am perfectly happy with my Logitech MX518 optical.

I have a Logitech laser mouse, and mine dosen't even show a laser period. Which one do you have? I have a MX610 Laser Cordless mouse.

Chad.

Quote: Original post by tstrimp

Quote: Original post by adam_ospeaking of lasers, why do mice use them? Does it really need the high-powered light to detect something as obvious as movement? Or do I not understand this correctly?

They are for higher resolution then a standard optical mouse. Whether they actually make a difference or if it's just hype I'm not sure. I am perfectly happy with my Logitech MX518 optical.

It does seem to make a difference. A regular optical mouse (with a red led) is clearly less precise. Even if it has "high precision", if you move the mouse VERY fast (faster than you would in any normal situation), the cursor sometimes jumps up or down in another direction.

With the laser mouse I have been trying to move the mouse the fastest I possibly could, and the cursor has always correctly followed these movements.

However, these differences are only in situations where you move the mouse faster than in normal usage situations. It could matter for gaming.

The laser in a laser mouse is invisible because it operates at an infrared wavelength of around 850nm. Visible light lies between about 400mn and 700mn (although this varies from person to person).

High power infrared lasers are dangerous because you can't see them, so you don't know they are damaging your eyes until it's too late. Even though you can't see the light, the intense concentration of energy can still damage the sensitive cells in your eye.

The laser in a mouse though is pretty low power (certainly less than 1mW), and the mouse will have safety systems built in to turn off the laser when you lift it up. You could still do something stupid like put it right up to your eye, so the mouse detects the surface of your eye as a valid surface, and turns on the laser. Don't do this, unless you are trying to make yourself blind.

From what I've read, the laser works better than an LED because it emits a very pure single wavelength of light that is much more accurate to track on a various different surfaces; especially shiny ones.

This mouse has quite a high DPI and no switch to change it. In both KDE in Linux, and in MS Windows, the very lowest accelaration/speed setting of the mouse cursor is required to have it operate at a sane speed. I'm wondering what would happen if mice have an even higher DPI later? Is OS support required to have sane speeds then?