DIY Fluid Goggles

[Pezman]

I did a little experimentation and found that a 10x Bausch & Lomb jewler's loupe seems to have the right optical properties. Just fasten 2 loupes to some clear swim goggles, drill some holes the side of the loupe to let the water in and there you go. The goggles can be filled with some nice, clean saline solution or whatever your eyes prefer to swim in.

Surplus loupes can be purchased for under $5 each.

I think I'll stick with a mask, but I plan to start carrying a loupe as a back-up in case my mask gets flooded, knocked loose etc.

 

[aydin]

Hello Pezman,
I wiil be waiting for the result,and can you please send me the picture of your googles..
Aydýn

 

[donmoore]

Mike,
Where do you buy Surplus loupes at?
don

 

[Pezman]

Loupes can generally be picked up at a camera shop or hobby shop. To test the loupe, fill it with water and hold it over your eye -- then look around. If you can see, then it's right for you.

If you fasten the loupe to goggles, then you may need to adjust the focus by (1) using a slightly less powerful loupe (i.e., lower magnification) or (2) trimming a bit off the back of the loupe in order to move it closer to your eye (i.e., the goggles added a little distance between the lens and your retina, so you need to compensate for that by shortening the loupe).

A cool variation would be to put the lens on a little arm that can be used to swing the lens in front of your eye to see underwater and flip it up when you surface. Loupes that are designed to fold into a case would be ideal for this.

Very simple, very cheap, surprisingly efffective. I'll build a few prototypes and post photos.

 

[tanteh]

Inside or Outside?

Hi,

recently I tried similar things and found some lenses that worked.
Testing the lenses only by filling them with water and looking through it is not sufficient approval for the funtion under water, I think. If you attach the lens at the outside of your mask the refraction changes and results in a "different" lens.
In my opinion it is better to attach the lens inside the mask, so you can clearly see in- AND outside the water.

Am I right?

Cheers, Carsten

PS: Newly infected, I will check it out with a pair of 10x lenses and tell you in advance...

 

[loopy]

Hey guys - sounds like an interesting prospect... have you looked though at the potential damage you can cause your eyes by not having lenses that are exactly right? Like how if you wear someone elses glasses, you can damage your eyes?

 

[tuomo]

I don't think that you can actually damage your eyes very easily with those. You will most likely get a nice headache if the lenses don't work for you. You should stop using them if that's the case. Just as contact lenses are very rarely excactly same as regular glasses.

Sounds like very interesting project. Please post some photos and testing results when you have any.

Tuomo

 

[Pezman]

@Tanteh

As long as there is no air in your mask, filling the loupe with water seems to be a valid test. I am not sure why this is so, since I would expect adding water to the outside of the lens to change the focal length, but this does not seem to be the case. When you add water to the outside, it does seem to reduce the magnification of the water-filled loupe (which is a good thing).

My plan is to make open-goggles that allow the lens to swing in front of my eyes when I'm under -- that way I can just flip the lens up when I'm on the surface and lower it when I'm under water. The only problem with this approach is the risk of infection or eye irritation when I'm in unclean water, in which case I'll use the old-fashioned, air-filled mask (and keep a loupe handy for emergencies).

While on the topic of masks, note that everything changes when your eye is "in-air" vs when it's "in water", which may be the issue that you are addressing in your post. In that case, the lower index of refraction of air makes it easier for a lens to do its thing and more importantly, your cornea and lens actually function. When you are in water, the index of refraction of the cornea, aqueous humor and lens are very close to the index of refraction of water (1.33), which means that they cannot focus at all. This makes us infinitely far-sighted under water. When you add a glass lens to this system, the problems caused by water actually become potential benefits because the close match between water's index of refraction and that of the eye's focusing mechanisms effectively eliminates them from the equation. That means that if you have vision problems that are related to anomalies in the shape of the cornea/lens etc, they are eliminated as well.

At any rate, it is easy enough to experiment with this -- just grab a 10x loupe and jump in the pool

 

[tanteh]

ui

Thanx Pezman,

for this detailed reply. The first Fattahs Fluid-Goggles were available in three versions:
1 made you see only under water
2 you could see under water with one and on surface with the other eye
3 you could see with both eyes in any situation

No 3 was the most expensive (and now the only available). I think the reason was the more complicating construction.

But as you said: When it works with a 10x Loupe - why bother?

Cheers,
Carsten

 

[Pezman]

Tanteh,

I re-read your post more carefully. I think that you are saying that if you use a lens that is flat on one side and curved on the other, and arrange it such that the convex side points into the fluid, towards your eye, that the system will allow you to see both in and out of the water. I believe that you are correct on this point.

I have attached a crude sketch (w/ apologies to Homer Simpson).

 

[loopy]

Pez - Eric goggles are the other way around. The curve is pointed away from the eye, and the lenses are inside the goggles.

 

[tanteh]

@ Pezman

Yesss!

Thats what I tried to say with my few english words.
I tried to glue a loupe into a goggle that way. It operated fair to middling.
Maybe someone is able to calculate it? I will give it a try in the cold months of winter...

Cheers, Carsten

 

[tanteh]

www.fluidgoggles.de

Here it is!

On Eric Fattahs site there is a description of his goggles:

... fluid goggles have special lenses mounted inside them ...

Take a look at the pictures attached. I think the loupes are inside!

Cheers,
Carsten

 

[DGP]

Hi guys,

Fred Buyle just sent me a quick message about this thread and since I have always hated "reinventing of the wheel", I thought I'd see if I can offer some help on the matter of DIY fluid goggles:

A few years ago I built a pair for Martin Stepanek that he used to set his 90m record for Free Immersion in the Caymans. We had NO money for the record (as you can read in Paul Kotik's great article "Reality Czech" here on Deeper Blue) so we could not afford to buy a pair of Eric's. So we decided to roll our own.

Not being an optical engineer and not wanting to become one so late in life, I decided to find someone who could help. To make a wonderful but long story short, I managed to contact one of the world foremost optical scientists at the Max Planck Institute (Why not start at the top, huh?;-).. Anyway, this wonderful gentleman took up the gauntlet and, after a bit of computer re-programming, gave me what I needed: the part number of a cheap lens that does perfect duty in Fluid Goggles.

When they first arrived, I donned only a swimsuit, jumped in the pool, held one up to my eye and, Voila, instant almost perfect UW vision with no mask! Way Cool.

Mounted on standoffs the way I made Martin's, there is no halo/spherical abberation and the vision is wonderful. You could glue them to flat plates and that plate to standoffs but what we did was to cut some acrylic tubes into curved sections about 22m high with small notches to hold the lense edge (so they can be removed) and mounted two of these standofffs for each lens, securing them in place with non-acid based silicone (aquarium) sealant.

You MUST use high quality goggles with a flat front and real face to the lens. The ones in the picture are the older TYRs that I built with Martin.

Hope this helps!

Doug

 

[Pezman]

You are so-totally-the-man!

Here's a link to a place where you can buy them:

http://www.edmundoptics.com/Buy/Cart-Add.cfm?itemid=10371

 

[kook]

I've ordered a pair of the lenses, thanks for that DGP. I didnt really understand your description on how to mount them. What do you mean by 'stand off' and what is 22m? Do you possibly have any closeup pics from other angles? Or if anyone else has any luck in mounting them please could you post your method. Thanks
Kook

 

[donmoore]

Thanks for sharing Doug. Your optical knowledge is way more than mine. I have that old age far sighed disease. The doc has me wearing reading glasses with at +1.5 to read. He says my eyes don’t have enough stigmatism to warrant the extra cost of prescription glasses. If I’m going to order lenses and make my own, where can I found out what lenses to get to that will give me a +1.5 underwater?
don

 

[Pezman]

@don

Your astigmatism should go away under water, since it is a refractive problem in the eye and your eye's refractive elements hardly matter underwater (which is why we need lenses).

@kook

I am guessing that the stand-offs were used to hold the lens away from the surface of the goggles. This would allow the fluid in the goggle to competely surround the lens and it eliminates the possibility of an air bubble. It probably also adjusts the focus of the sysetem a bit, putting the lens very close to the eye. In fact, by making a stand-off that allows the distance between the eye and the lens to be adjusted, I think that the lens can be "tuned" so that you can compensate for vision problems ike nearsightedness and farsightedness.

Hmm, per Doug's post, it seems that I put the lens in backwards

 

[DGP]

Pezman,

GOOD GUESS!

but you have precious little room for the lens and mount in there but yours may well work.. I'll take a lens in the pool and see!<G>

Like I said, you guys take the ball and run with it. You may easily come up with a better mousetrap and when you do, please let us know!

Doug

 

[kook]

thanks very much for that doug & pezman. i look foreward to the chalange of assembling. hope they arrive soon. if anyone else gets theirs before mine please post your progress in assembling and reviews of there performance. i bet there will be a lot of interest in this. thanks again
kook