be careful with specular reflections of the laser. ebay trash is always mislabeled for power. My "5mW" 405nm pointer emits 70 mW on new batteries as measured with a good power meter. if the 200mW unit is really emitting 500mW, the 2 side Fresnel reflections from a thin piece of glass will be 8% or 40mW. 40mW of coherent 405 light is much more dangerous than the same amount of 632nm light or 1064nm light, it will instantly burn the retina if focused to a diffraction limited spot due to the high absorption coefficient of retinal tissue at green-blue-violet wavelengths. a red or IR beam of the same power will penetrate deeper into the red tissue of the retina and deposit its heat over a larger volume, giving you much more of a chance to escape without cell damage. laser goggles are important at hundred plus mW powers but any of the good "blue blocking" glasses popular for "reducing eye strain" these days will afford you with some protection. test them by shining the beam through the lenses onto a piece of white paper as seen in the many "blue cut glasses test with laser" videos on here.
I am going to test this laser pointer on a power meter, to see what the actual energy is. You are absolutely correct in how important safety goggles are.
I want to look directly into the laser.
be careful with specular reflections of the laser. ebay trash is always mislabeled for power. My "5mW" 405nm pointer emits 70 mW on new batteries as measured with a good power meter. if the 200mW unit is really emitting 500mW, the 2 side Fresnel reflections from a thin piece of glass will be 8% or 40mW. 40mW of coherent 405 light is much more dangerous than the same amount of 632nm light or 1064nm light, it will instantly burn the retina if focused to a diffraction limited spot due to the high absorption coefficient of retinal tissue at green-blue-violet wavelengths. a red or IR beam of the same power will penetrate deeper into the red tissue of the retina and deposit its heat over a larger volume, giving you much more of a chance to escape without cell damage. laser goggles are important at hundred plus mW powers but any of the good "blue blocking" glasses popular for "reducing eye strain" these days will afford you with some protection. test them by shining the beam through the lenses onto a piece of white paper as seen in the many "blue cut glasses test with laser" videos on here.
I am going to test this laser pointer on a power meter, to see what the actual energy is. You are absolutely correct in how important safety goggles are.
wow