Laser Injury 532nm 400mW / Kaleidoscope Attachment Affect Power?

[FSainzo9595]

Hi Community,

I'm very thrilled to have found this forum as I've been unsuccessfully searching for some answers. If you have a moment I'd be so so appreciative of some feedback, thanks for your time.

For anybody interested the whole story is below, but my main ask is: Does a Kaleidoscope attachment on a laser attenuate the power of each point on the output?
For example: if the attachment on a 400mW laser produced a 10x10 grid, is each point 4mW? (See attached images)

In short: I was hit in the eye by a 400mW 532nm laser at 5-10ft distance. This happened days after NYE when my clown co-worker brought in said laser. I was too busy reading a paper in my hand to notice the grid in front of me and turned right into him firing the laser, it caught my right eye and I winced but not before looking right into it. The caveat is that the laser had a Kaleidoscope attachment and was emitting a patterned matrix so I was only hit by a single element of this. Was my eye subjected to less than 400mW? I can't find any information on this type of scenario.

I didn't think anything of it initially and never imagined him bringing that kind of laser into our place of work. I began noticing some mild visual disturbances in the form of Metamorphopsia/center vision issues which is why I'm investigating. I conveniently went to an Ophthalmologists last summer and just had a full work up post incident. The optical coherence tomography (OCT) and retinal fundus are identical to before the injury and the Dr. assured me there was no indication of retinal injury

Sorry for the novel and if you have any insight to offer I'd be very grateful. I'm hoping that once I understand just how much power my eye was subjected to I can reconcile this and move on. Thanks again for your time/input.

 

[julianthedragon]

It's good that you've seen a doctor already as we can't give medical advice. Usually with those kaleidoscope attachments the power of each beam is a fraction of the total power but the beams near the center will still be the strongest. On top of that it's hard to tell exactly how powerful it was since power is often mislabeled on lasers and it wasn't measured with an LPM. Was it one of those holiday decoration lasers that people shine at their house?

Assuming the total output power was 400mw and you were hit by one of those beams, it was a lot less than 400mw.

 

[FSainzo9595]

Hey! Thank you for your input I very much appreciate the response.

Unfortunately the device was a seemingly well built pointer powered by a 18650 Li-ion battery.
The metal housing was milled professionally, heavy, and included safety keys. At the time the guy said
he paid more than $100 for the laser.

I wish I jotted down the part # but have since laterally moved positions, partly because of this negligent bs(not the first instance).
At the time I looked up the spec sheet and it was class IIIb 400mW, I really hope the power was embellished but I worked at an
engineering firm and the "toys" people brought around tended to be more than.

I remember seeing the laser grid on the wall before turning around and was center of it, I suspect this clown was pointing it right at me and I beat myself up for not realizing what was going on.

How does the power fall off with distance from the center?

I know very little about optics but from my research I think that if I took a full 400mW at 5-10ft I would be having more severe issues right now. I experienced no aftering or flash blindness after the incident but the Metamorphopsia/center vision lacking seemingly came on as a result however has marginally improved over time. I also underwent LASIK a year ago and think the focused light may have enhanced any injury potential.

Thank you again for your time and feedback.

Edit: I also saw the laser pointed at a wall at 1ft distance without the kaleidoscope attachment, I was at a severe angle. The diameter of the beam was about 1 Inch not sure if this is relevant.

 

[Unown (WILD)]

I'm hoping that once I understand just how much power my eye was subjected to I can reconcile this and move on. Thanks again for your time/input.

I'm not sure what you're looking for here from us. If you saw a doctor and he said you are fine and you don't feel any different then what's the point of this?
Just trying to understand

 

[julianthedragon]

How does the power fall off with distance from the center?

Again, even with the exact formula for this, it wouldn't confirm how much power you were exposed to because there are so many unknowns. If it brings you peace of mind, the fact that you feel okay and your issues are improving is a good sign. It's also good that he didn't point a full 400mw directly in your eye. Did your coworker realize what happened or ever apologize?

 

[CurtisOliver]

>>>Warning<<<


"If you think you need medical help or attention for an eye injury or any other medical problem, you probably do."
"If you have been hit in the eye with a laser and feel you have suffered any type of eye injury as the result of an accident with a laser that may need medical opinion or treatment,
go to a hospital Emergency Room and/or consult a qualified Board Certified MD Ophthalmologist ASAP.
LPF is a laser hobbyist website, not physicians, and cannot give any medical or legal advice.
No professional medical or legal advice is available or possible on LPF"

For additional information see laserpointersafety.com here:
Laser Pointer Safety - What to do if you are hit by a laser pointer or laser pen​

 

[FSainzo9595]

I'm not sure what you're looking for here from us. If you saw a doctor and he said you are fine and you don't feel any different then what's the point of this?
Just trying to understand

Hey thanks for the reply, I'll try to help you understand the best I can. I don't fully feel fine and am experiencing a degree of asymmetrical visual disturbance as mentioned in my post.

Modern medical imaging has thresholds of detection and my suspicion is that there was some minor injury from this all.

I know the brain is good at filling these gaps in and I'm grateful this accident hasn't left me in a more serious place.

I'm trying to understand how a kaleidoscope attachment affects power to estimate what fraction of 400mW was my eye exposed to

Hope I was able to provide some insight.

​

 

[Unown (WILD)]

Hey thanks for the reply, I'll try to help you understand the best I can. I don't fully feel fine and am experiencing a degree of asymmetrical visual disturbance as mentioned in my post.

Modern medical imaging has thresholds of detection and my suspicion is that there was some minor injury from this all.

I know the brain is good at filling these gaps in and I'm grateful this accident hasn't left me in a more serious place.

By trying to understand how a kaleidoscope attachment affects power my aim is to quantify this whopping/distressing unknown in my
life which is "what fraction of 400mW was my eye exposed to?"

I know there's a huge psychosomatic element to this and by putting a rough number to it I'm hoping to differentiate psychological worry
from fact:/

Hope I was able to provide some insight.

​

I'm sorry that you may have some damage to your sight but I need to give you some of insight of our own. We are not doctors here. We will not give you any advice because we are not qualified to do so. We do not want to be liable for any misinformation that may lead to further injury. You've been told to continue getting professional help. There's nothing more we can do for you. You got hit in the eye from a coworkers laser. Nothing more to understand. The discussion is closed

 

[CurtisOliver]

Please see my post above. We cannot give medical advice on LPF. If you genuinely suspect something is wrong, you go and get it checked out by a medical practitioner. If you have done this, and everything is ok. Then count your lucky stars and learn from any mistakes.

 

[FSainzo9595]

I'm sorry that you may have some damage to your sight but I need to give you some of insight of our own. We are not doctors here. We will not give you any advice because we are not qualified to do so. We do not want to be liable for any misinformation that may lead to further injury. You've been told to continue getting professional help. There's nothing more we can do for you. You got hit in the eye from a coworkers laser. Nothing more to understand. The discussion is closed

Hi I'm not looking for medical advice whatsoever and as mentioned my main ask is:

How does a kaleidoscope attachment affect the power output of a laser? This is a purely scientific ask and I think
a well suited question for the community. Please do not close this discussion.

​

 

[Unown (WILD)]

Hi I'm not looking for medical advice whatsoever and as mentioned my main ask is:

How does a kaleidoscope attachment affect the power output of a laser? This is a purely scientific ask and I think
a well suited question for the community. Please do not close this discussion.

​

You are asking us for psychiatric analysis which still falls under what we have told you... Get professional help. If you had simply asked about the diffraction attachment on a laser then sure that's perfectly fine but you also asked about a few other things. Quoted from you bellow -

By trying to understand how a kaleidoscope attachment affects power my aim is to quantify this whopping/distressing unknown in my
life which is "what fraction of 400mW was my eye exposed to?"

I know there's a huge psychosomatic element to this and by putting a rough number to it I'm hoping to differentiate psychological worry
from fact:/

​

Go see a Psychiatrist to help you quantify this distressing unknown in your life. We cannot help you.

 

[FSainzo9595]

Please see my post above. We cannot give medical advice on LPF. If you genuinely suspect something is wrong, you go and get it checked out by a medical practitioner. If you have done this, and everything is ok. Then count your lucky stars and learn from any mistakes.

Hi thank you for your reply. I am not looking for medical advice and have taken the proper medical steps in response to my incident.

I am solely asking the community for any information on "How does a kaleidoscope attachment affect the power output of a laser?"

My question is purely scientific and related to the workings of lasers, nothing more.

 

[CurtisOliver]

The nature of diffraction gratings means that if you had 40 dots, if would not mean however that each dot is 1/40th of the initial power.
The power distribution would mean the central region being the most intense, with the outer dots being less intense.



See a visual example above

 

[FSainzo9595]

The nature of diffraction gratings means that if you had 40 dots, if would not mean however that each dot is 1/40th of the initial power.
The power distribution would mean the central region being the most intense, with the outer dots being less intense.

View attachment 74342

See a visual example above

Very interesting and informative thank you. Intuitively I felt that it couldn't be as simple as "each dot is 1/40th of the initial power"

Is there a formula or general rule of thumb that models how the power falls off from the center?

 

[CurtisOliver]

Single Slit Diffraction Intensity

This is for a singular axis diffraction pattern.

 

[FSainzo9595]

Again, even with the exact formula for this, it wouldn't confirm how much power you were exposed to because there are so many unknowns. If it brings you peace of mind, the fact that you feel okay and your issues are improving is a good sign. It's also good that he didn't point a full 400mw directly in your eye. Did your coworker realize what happened or ever apologize?

No this guy is a fully ignorant buffoon and I wasn't going to appeal to any reason of his because he has none. I chewed him out and he acted as if I was overreacting.

Do you have any quantifiable info/ experience with how power falls off from the center? Even an estimation in order of magnitude?

Thanks