I wa at this store with furniture and saw this control and was looking at it and in the middle of one of the buttons there was a really bright green light under it and it felt like it stunned me I wonder if there is a laser it was green why would it be there . This is the controller in question https://www.walmart.com/ip/Tranquil-Ease-Recliner-Handset-with-Heat-and-Variable-Massage-2802/147028929?wmlspartner=wlpa&selectedSellerId=1007&adid=22222222228042195310&wl0=&wl1=g&wl2=m&wl3=61350584618&wl4=pla-101576556338&wl5=9052126&wl6=&wl7=&wl8=&wl9=pla&wl10=112354429&wl11=online&wl12=147028929&wl13=&veh=sem
closed as off-topic by Leon Heller, The Photon, Chris Stratton, duskwuff, RoyC Apr 1 at 8:41
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." – Leon Heller, The Photon, Chris Stratton, duskwuff, RoyC
Efficacy of LED's has improved greatly over the last couple decades and many inexperienced designers fail to understand that "indicators" now are stunningly bright at rated current.
Earliest generations were GaP green with Gallium Phosphide and had intensities of 10 to 100mcd per 20 mA in a typ part.
Keep in mind the millicandella [mcd] brightness increases less than double for half the beam angle due to lens magnification (gain), with the "less than" 10% part, due to optic loss for each octave (/2) of angle reduction.
2nd generations were AlInGaP with a transparent substrate that alreflected the back reflected cup now standard but with Aluminum in the mix of semiconductors to improve efficacy while raising the forward voltage and reducing the wavelength slightly (less deep green)
Deep green is 525nmD ( read nanometer, D = Dominant wavelength (eye corrected), not the peak wavelngth (nm P) due to photodiode amplitude, because our eyes are most sensitive to green but equalized for white.
The 3rd generation of Green LEDs are InGaN. These are the most bright gtreen now in LEDs with Luminous Intensities, (Iv) of up to 50,000 mcd at 20mA. The addition of a bit of Indium increased the efficacy of green and this is common now.
Someone didn't know the difference between choices of LEDs and chose or substituted an LED that may have been cheaper now but much brighter than the design intended or the designer didn't know any better and just made it "stunning" to put your mind at focus away from your aches and pains. ( inflict eye pain to forget the rest) If the sight of staring at an LED leaves an inverse colour impression after looking away, this your Eye's "AGC" adapting to saturation and it will return to normal hopefully in 10 minutes.
If it hurts, don't do it.
Some LED's at close range can cause eye damage. Designer/ Users beware and use only 2~3mA for these 5~50 Candella class of 20mA indicators for close range. Of course if you want for a distant indicator, good choice. Hopefully you are over-reacting but beware anyways. "ALso designers" include the important attributes in the part description so buyers dont make bad choices in cases of loose design BOM controls. Eg. 5mm Deep green 30 deg 525nmD 10 Cd
If I get the chemical names wrong for each generation, forgive me , I am old as dirt. Now go calibrate your eyes to 1 Candella at 1 meter for each colour at indoor light levels. Stun guns off... no more drama.