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Comment by hammock | Hacker News Reader

Are LIDAR dangerous to the eyes of other drivers or pedestrians?

1550nm LiDAR Damaged Sony Camera at CES - http://image-sensors-world.blogspot.com/2019/01/1550nm-lidar...

Thanks for sharing that, clearly there is something at least worth investigating here. The concern about long-term exposure to LiDAR beams is not extensively studied. Current regulations seem to primarily focus on short-term exposure limits, and there is a lack of comprehensive testing under real-world conditions

No, there’s a class system for laser safety

The rating is for you to stick your eyes right up to it for a long period of time and still be fine

What’s “a Long time”? Does it cover a 2 hour commute in traffic with 20+ cars around you blasting it continuously any direction you look, invisibly?

Laser safety ratings are based on what would happen if the laser was pointed directly at your eye continuously. In the case of general traffic each lidar is scanning in different direction and while manufacturers try to make the energy produced by their lasers instantaneously brighter than the sun in one specific wavelength but damage to your retina is caused by excessive heating and doesn't care about what wavelength the energy is coming in at in the IR except to the extend that it can get to the retina or not. In your morning commute I'd worry less about the lidars than the much larger amount of invisible IR radiation given off by the sun. And I'd worry much less about the sun's IR radiation than the sun's UV radiation, wearing sunglasses during a 2 hour commute is best for your eyes.

They should not be. In theory they can be, but there are strict regulations to prevent that.

What are the regulations and who are the relevant regulatory bodies? I could not find with a google search

They fall under the same regulations as lasers.

Those can be gamed easily.

Please explain!

Laser damage is notoriously difficult to predict due to a statistical nature of thresholds. There are many tricks and non-trivial ideas that can make the device certified eye safe, even if it emits a high laser power. These obviously wont be discussed willy-nilly on random forums.

Good question! You're right, this is surprisingly hard to Google. It looks like the FDA is responsible. I would not have guessed that!

The National Highway Traffic Safety Administration (NHTSA) would have been my guess, but I'm not finding much there. They have a spec for LIDAR speed measurement devices, and one for the required sensors in vehicles, but nothing on the the output of said sensors.

> For manufacturers of laser products, the standard of principal importance is the regulation of the Center for Devices and Radiological Health (CDRH), Food and Drug Administration (FDA) which regulates product performance. All laser products sold in the USA since August 1976 must be certified by the manufacturer as meeting certain product performance (safety) standards, and each laser must bear a label indicating compliance with the standard and denoting the laser hazard classification.

https://www.lia.org/resources/laser-safety-information/laser...

https://www.fda.gov/radiation-emitting-products/home-busines...

https://www.fda.gov/about-fda/fda-organization/center-device...

Sorry, I don’t believe the FDA is doing anything more than stamping a Class 1 or class 2 sticker on component parts. They are not testing LIDAR arrays in situ under simulated driving conditions

I would like to see crash test dummy style research around vehicular LIDAR

Crash tests in the US are also technically on the honors system too, but NHTSA does test the most common models. But many they don't. For example, the Cybertruck.

Classification should be sufficient. Remember that LIDAR is invisible, so distraction or flash-blindness are not relevant, just health effects. Class 1 has already been thoroughly tested and deemed "safe even for long term intentional viewing." Class 2 is visible only, so any LIDAR systems above 5mW would be Class 3, which are deemed harmful to humans. You can put a Class 3 laser in public (see laser light shows) but the FDA regulations require an indicator and to give the public enough warning to get clear if desired. These restrictions are going to make anything but Class 1 LIDAR exceedingly difficult for use in automotive applications.

I know we are talking about car type lidar, but the iPhone Pro has a type of one and gets a depth map of photos. So you’re shooting it everyone you are taking photos of.

I don't think the Lidar in apple's stuff is actually a lidar, I think its a structured light sensor.[1]

What do I mean by that? lidar sends pulses of light and works out the difference between emission time and arrival time to work out how far the pulse has travelled.

The structured light sensor emits a pattern or dots, and any distortion of that can be used to compute the shape of an object.

[1] https://image-ppubs.uspto.gov/dirsearch-public/print/downloa...

They aren't talking about FaceID.

iPhone 12 introduced a lidar sensor in the back.

https://www.nature.com/articles/s41598-021-01763-9

if you actually read the paper you linked, you can clearly see the structured light pattern emitted by the laser. (https://media.springernature.com/lw685/springer-static/image... or figure two.)

Also the patent I linked was filed in 2020, after faceID was rolled out.

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