I just made a pair of these goggles today, and found it an amazing experience walking around outside with heavily filtered vision.

It's a very hot, bright Australian summer's day today, so a huge amount of IR to work with. I made the filters up with 7 laters of Congo Blue, and 2 of the Primary Red and experimeted a bit adding and removing layers.

What amazed me was the difference between my experience and my girlfriends. An experience which gives some credence to the view that Near-IR or IR can't easily be defined as light we can't see, but instead has to be defined by wavelength. You see, my girlfriend couldn't see much at all. To her the world looked very dark, and grass and trees were just visible and looked greyish.

To me the world lit up like a Sci-Fi wonderland. Concrete and rocks were black, the grass and trees white, and black clothing went grey/white. I experimeted a little, taking the red filters out to give myself some diferent effects and found that the world changed again , now black and green things were BRIGHT orange, almost flourescent like orange flouro under a UV light would appear.

I tried my girlfriend again. She still just saw a dark world, even after I made her stand with the goggles on for some minutes outside in the bright sun. Whereas my eyes, instant adaption, and a vivid and sureal world.

I was even able to make my way around inside, just. Regular globes in teh house glowed a deep red, and flouro lights where a purplish UV/Blacklight colour.

So it's clear to me that with Red & Blue filters I'm getting a pretty much IR heavy view of the world, and with teh Red removed the view is made a little more colourful, but still so completely different the presence of wavelengths not normally registered is obvious.

Ohh, and just for the sake of those wondering what it all cost...

The Gel filters, biught in sheets cost me a total of AUD$30 and the Welding goggles with removable lenses cost AUD$28. I have HEAPS of filter material left, so I'll possible auction of strips, enough to make a set of lenses on Ebay to recoup some costs.

My next step is to get some deeper blue and try and drop the passed wavelength down even lower and see what I can see.