1

I took off the head of my FW3A to change the optic and in the process slightly touched the lens. I took some windex with a microfiber cloth and wiped it but now I’m wondering if I might have affected the AR coating somehow in the process. What techniques do you guys use to clean your AR coated lenses?

2

I use my glasses cleaning fluid and a microfibre cloth.

I reason that if it doesn’t mess up the AR coating on my glasses - so far, so good - then it shouldn’t mess up the AR coating on my flashlight lenses.

One thing that occurs to me: make sure the lens is bone dry before assembling it into a light, or you may end up with corrosion from humidity on places like aluminium reflector coatings.

3

I clean my AR lenses the same way you did blind-eye, never noticed any issues. I think they are pretty durable.

4

An optician once told me that all glasses with AR coatings come with anti-scratch coatings as standard, because the AR coating is relatively fragile. If flashlight lenses are the same, then the coating should be pretty durable in reasonable use.

5

Use eye glass cleaner works great drys fast and doesn’t leave and streaks are resident

6

One of my other hobbies is bird watching, which requires binoculars with all kinds of lens coatings. Zeiss makes cleaning wipes that are designed not to damage coated lenses. A box of wipes (don’t remember if its 25 or 50 one time use to a box) is under $5 at Walmart.