How long does it take a laser pen to do damage your eyes?

It depends on the power of the laser pen and the length of time it is pointed at the eye. Generally speaking, a laser pen with a power of less than 5 milliwatts (mW) is not considered to be dangerous, and it would take several seconds of direct exposure to cause any damage to the eye. However, laser pens with a power of 5 mW or more can cause permanent damage to the eye in as little as a fraction of a second.

Here are some tips for safe laser pen use:

- Never point a laser pen at anyone's eyes, even if you think it is "safe".

- Keep laser pens out of the reach of children.

- If you are using a laser pen for presentations, make sure that you are not pointing it at anyone's eyes, even if you think they are not looking.

- If you are ever accidentally exposed to a laser pen, immediately close your eyes and seek medical attention.

Here are some additional resources on laser pen safety:

- American Academy of Ophthalmology: Laser Pointer Safety

- The Laser Institute of America: Laser Safety Information