UPDATE 10/5/2022 – J Tech has designed and produces it’s own goggles, so no need to worry about our quality.
When looking for laser goggles, it is easy to find many vendors supplying them at low cost prices, just look out for what you are going to get. Quality of these goggles is probably suspect if you can find them for under $10 and they most likely are not going to be tested. Here at J Tech Photonics, we test every pair of goggles that comes into the lab. The specification for testing is outlined in ANSI Z136.7, and while many of the goggles found on EBay, Amazon, and other internet retail sites may have them printed on the lens, they do not meet the requirements outlined in the specifications.
The last shipment of goggles just got in yesterday from our China supplier and we proceeded to test them. Every single pair did not pass our quality and ANSI specification testing. We are taking the hit on the financial side and are also now switching to a U.S. supplier to ensure our high standards of quality are met.
When looking at Amazon for laser goggles or other sites like alibaba, understand that you are getting a product that might look like laser goggles from the outside, but they can be lacking in the quality needed to be able to see clearly through them and also reflect or absorb the harmful reflected laser radiation.
Lens Quality Tests
Many of the China suppliers for so called “laser safety goggles” use the cheapest injected molded plastic that is not optical quality. Using a USAF visual target, you can see the difference when looking through the lenses. Below you will see the target by itself, the target looking through a Chinese goggle with cheap plastic, and looking through an U.S. supplier with optical grade plastic lenses.
It is important that when using a product that is supposed to protect your eyesight that it is clear enough for you to be able to see what you are doing, especially when operating high power lasers!
Here in the optical testing lab, we also test every goggle that comes through the building to make sure it meets the O.D. (optical density) requirements outlined in the goggle specification sheet. This is the requirement for how much light is transmitted through the laser goggle. It is also sometimes called absorption, but in many cases the goggle works by reflecting light as well. From Wikipedia on this subject:
Absorbance is a quantitative measure expressed as a logarithmic ratio between the radiation falling upon a material and the radiation transmitted through a material.
where is the absorbance at a certain wavelength of light (), is the intensity of the radiation (light) that has passed through the material (transmitted radiation), and is the intensity of the radiation before it passes through the material (incident radiation).
So, for an O.D. of 2+, it should have an attenuating factor of 100 times. That is saying 1W of optical power should only let through 10mw at most of radiation. This is of course of you accidentally looked right into the beam, which you shouldn’t. However, it will save your eyesight if does happen. A more reasonable case is taking a reflection of the laser beam from a surface at 20mw and then only transmitting 0.2mw of radiation to your eye.
Every goggle is tested to make sure this specification is met.
Important Take Away
Take care to make sure you purchase high quality laser goggles whenever using lasers or laser devices. Always make sure you wear your goggles as well as everyone else in the room to keep the dangers of stray radiation at bay!