More and more people are interested in building and experimenting with IR laser setups.
Looking through the treads on NUI Group, I’ve seen a lot of warnings (from various people) about potential damage that the IR laser can cause to your eyes.

I believe that we are all here on this group because we not olny have sufficient technological insight and knowledge, but also a good common sense. So please use it when working with IR lasers.

The light from the IR laser modules is invisible and because it does not cause any blink response, it will damage your eyes if looked directly into it.
Always use laser IR blocking protection glasses when working with lasers!!!

Neither I nor anybody else on the NUI Group will be responsible for any injury or damage to anybody caused by a missuse of these IR laser modules.
Please use these IR laser modules in a safe and responsible manner!

UPDATE: Please read the laser class information below.

~Alex

Thanks for the warning, i’ll be sure to be carefull..

Some extra cautious with lasers from a CD/DVD players, even though they are labelled as Class 1 ("eye-safe under all operating conditions") this is only because they are housed and are not directly exposed, officially these laser are often Class 3R/3B and therefor dangerous.

Any laser product of a given Class may contain ‘embedded’ lasers which are greater than the Class assigned to the product, but in these cases engineering controls (protective housings and interlocks) ensure that human access to radiation in excess of product Class is not possible. Notable examples of this are CD and DVD players which are Class 1 laser products while containing Class 3R or Class 3B lasers and laser printers which are Class 1 laser products but contain Class 4 embedded lasers.

Laser Class information

Out of interest Alex, what class would you say your lasers are?  And if we are spreading the beam using a lens surely the danger is reduced (once installed etc)?  Basically, lasers for a final product for the public to use will still be ok, as long as they can’t get their eyes into a position whereby they fry them.

Larky - 01 July 2008 02:04 AM

Out of interest Alex, what class would you say your lasers are?  And if we are spreading the beam using a lens surely the danger is reduced (once installed etc)?  Basically, lasers for a final product for the public to use will still be ok, as long as they can’t get their eyes into a position whereby they fry them.

You are correct. The laser’s total output power is spread evenly accross the light plane and the farther you go the lower the light intensity is.
Looking at the various specs and laser class definition, I would say that the 850nm 10mW IR laser modules fall into Class IIIb devices.
As a reference to this take a look at this document and this web page.

Here is the description of Class IIIb device taken from laser safety wiki page:

Old System

Class IIIb

Lasers in this class may cause damage if the beam enters the eye directly. This generally applies to lasers powered from 5–500 mW. Lasers in this category can cause permanent eye damage with exposures of 1/100th of a second or less depending on the strength of the laser. A diffuse reflection is generally not hazardous but specular reflections can be just as dangerous as direct exposures. Protective eyewear is recommended when direct beam viewing of Class IIIb lasers may occur. Lasers at the high power end of this class may also present a fire hazard and can lightly burn skin.

Revised System

Class 3B

A Class 3B laser is hazardous if the eye is exposed directly, but diffuse reflections such as from paper or other matte surfaces are not harmful. Continuous lasers in the wavelength range from 315 nm to far infrared are limited to 0.5 W. For pulsed lasers between 400 and 700 nm, the limit is 30 mJ. Other limits apply to other wavelengths and to ultrashort pulsed lasers. Protective eyewear is typically required where direct viewing of a class 3B laser beam may occur. Class-3B lasers must be equipped with a key switch and a safety interlock.

~Alex

Glad this is a sticky post/topic,
Prominent and Bolded so it’s easily seen by people,
unless it’s too late and they are already blinded.

Alex , have you experimented with 5mW lasers? With the line lense they should be the safest , falling between class 2b and 3a.

AlexP, thank you for warning the people on NUI Group for testing this specific solution. I appreciate it as well as all the others.

We’re looking into ordering safety goggles for the office. Since I would never want to be telling my grandkids “… and back in 2008, I was trying to build some LLP multi-touch surface and we saved $30 on safety glasses, and that’s why I wear this eye patch.” —I’d love some second opinions
Does anyone know if these would suffice:  http://store.oemlasersystems.com/index.php?main_page=product_info&cPath=8_10_16&products_id=46

Would it be possible to use a lower intensity laser?  I’d love to make a multi touch for my little girl and me to play with, but I can’t really reconcile the danger of damaging her eyes.