eyepiece laser safety filter and 3D printing

July 8, 2014 at 3:57 pm | | hardware, lab safety

With TIRF and lasers on many fluorescence microscopes these days, there’s a huge risk of seriously damaging your vision. Not so much from a stray beam (which is probably diffuse or your blink reflex will be faster than the damage threshold), but more from looking in the eyepiece without the proper filters in place. A reflected laser beam focused with the eyepiece lenses right onto your retinas can be vary damaging.

(That happened a Berkeley a few years ago, and EH&S asked everyone to take the eyepieces off their TIRF scopes. I removed one, so that you’d only lose one eye.)

Interlocks between your scope port setting and your laser is one option. But that means you can’t ever look at your sample with your eyes (at least the fluorescence). The elegant solution it to put a multi-band emission filter in your eyepiece tube to block any laser light:

eyepiece laser safety

I got this idea from Kurt, who even designed a filter holder that you can 3D print. I modified that part for one that would fit in our Nikon TE2000. (See edit and links at end of post.)

2014-05-13 19.28.12

I also printed some other parts for our TE2000. After we upgraded our epi illumination source from a Hg lamp to a Lumencor Spectra-X LED, we no longer needed the ND filter sliders on the illuminator tube, because the LED intensity is easily controlled by software. I’ve always hated those sliders, because they are easy to accidentally knock into the wrong position. That, and they aren’t encoded into the image metadata, so you have no idea what slider settings you had when you look at an image 3 months later!

2014-07-07 15.27.14

So I removed the ND sliders and replaced them with a nice plug to block the light.

I have my 3D designs on the NIH 3D Print Exchange.

EDIT: I also made a eyepiece-filter holder for the Nikon Ti2.

2 Comments »

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  1. Hi Sam I can’t believe I missed this! Excellent article and this is actually quite important for people to understand. I swear I’ve got floaters in my eyes from getting hit by so many scopes over the years. In fact, the FDA is constantly reducing the allowable amount of retinal exposure limits for retinal laser scanners! Good post man.

    Comment by Austin Blanco — January 9, 2016 #

  2. […] can’t believe I missed this excellent post from Sam Lord @ Everyday Scientist on how to insert an emission filter on your ocular lightpath. Having been hit by some untold number scopes wherein I either was observing, and switched to a […]

    Pingback by Austin's Imaging Blog » DIY emission filter for observer safety — January 9, 2016 #

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