I can't see things very well at a distance. I used to wear classes, then contact lenses, then nothing. I hadn't worn any corrective lenses for years because glasses were annoying and my contact lenses were messing up my eyes. One day I was thinking about the reason for near-sightedness and I figured that if it's caused by an inability of the eye's lenses to flatten out, then maybe I could physically assist them in some way instead of just optically correcting for the problem like 'corrective lenses' do. Then after trying some things I realized that I could pull back back on the skin at the sides of my eyes and this seemed to do the trick. Since then I've been in several seminars in which I successfully used this trick to be able to read the screen or chalkboard that was too far away for me to otherwise make out clearly. So I decided to make a simple device to do this for me. What I made probably wouldn't be something that most people would want to wear in public, but a professionally made, miniaturized version of such a device might have more widespread appeal, and it was fun to make and test in any case.
Note: Squinting is thought to work by decreasing the amount of light entering the eye as well as by slightly flattening the eye's cornea. The cornea is a lens of the eye that is responsible for a majority of the eye's focusing power. If one squints one can notice a decrease in the field of vision indicating a decrease in eye's aperture. However, when pulling at the eyelid corners with your fingers you will notice an enhancement of distance vision greater than that achievable by squinting, and without any noticeable decrease in field of vision. So it seems that this system works more by flattening the cornea than it does by decreasing the eye's aperture. A final possibility for how this system works is related to the eye's length: In near sighted people light from distant objects converges slightly in front of the retina (the part of your eye that actually detects the incoming light and sends the information to your brain). Using this system the pulling back on the eyelids may be compressing the eye slightly, thereby allowing the convergence of light rays to occur further back in the eye: at the retina, allowing clearer vision of the distant objects.
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= The first photo shows a portable CD player, you could also take apart a non-portable CD player but those are usually a little harder to take apart.
= The second photo show the inside of a CD player. The black region on the green board on the left is what you're after, it has all the necessary motors and gears attached.
= The third photo shows this same mechanism from the underside, showing the motors and gears. You do not need to disassemble this mechanism, you will use it as is. All you need to cut are the wires leading to the rectangular motor (as noted on the photo).
Looking at the third photo: We'll be interfacing with the rectangular motor which is connected to the worm gear which is connected to the laser lense. The laser lense gets moved linearly, up and down along the worm gear. A 'worm gear' is the best way to allow low torque motors (such as the small rectangular one in the photo) to be used in high torque applications (like this one), but some cheaper CD players won't use worm gears. These alternate gear configurations will also work ok for this application.
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Just as an aside, the way squinting works is to reduce the effective aperature of your eye. As any photographer knows, when you stop down the aperature, you make the aperature small, which increases the depth of field. This means that objects are in focus over a larger range of distances. Conversely, opening the aperature up reduces the depth of field, which allows a photographer to take a picture of a persons face, for example, with everything in front and behind out of focus.
A camera obscura (pinhole camera) works on the same principle, but with a very small hole as the aperature.
MrWolfe said:
"I am very myopic (not sure about "short sighted" - makes me sound a bit conservative!)."
Funny you should add a political comment like that, but since you brought it up... every conservative I know is very far sighted, they think about the effects of choices today and the consequences upon the future.
As to the narrow view through a pinhole, I'll try very hard not to make a comment relating a narrow view to the other kind of politics. ;)
[DISENGAGING TROLLING MODE NOW]
Probably not an issue for driving a tiny motor like that though as long as you use oversized transistors.
http://www.quickliftmd.com/
Want another way to correct nearsightedness? Ride in the leading car of a roller coaster and look straight forward! The air blast flattens the cornea. It corrected my 3 diopters of nearsightedness on the fast parts of the ride.
http://www.fda.gov/medicaldevices/productsandmedicalprocedures/surgeryandlifesupport/lasik/ucm061270.htm
Another question: would prolonged pressure raise the eyeball pressure, and damage the retina?
How does the idea sounds to hook that up to a microcontroller, combined with a distance sensor (and maybe a laser pointer to aim the target) for an automatically focusing?
If you want a product that sticks to skin tightly over a small contact area consider using half a "breathe-right" strip at side of each eye.
These have a sprung ? metallic centre section you could attach your mechanism to and are designed to hold your nostrils open to reduce snoring. I have seen some athletes use them too. To work they have to be very sticky and not come unstuck due to the spring effect, so might be good for your application. Also the adhesive is already licensed for use on skin.
Example:
http://www.superliving.co.uk/index.php?option=com_virtuemart&category_id=19&flypage=flypage.tpl&manufacturer_id=77&page=shop.product_details&product_id=1845&Itemid=45&vmcchk=1&Itemid=45
There are probably none small enough for what you want but the principle might be quite neat as minimal moving parts near your eyes, control unit of some sort in your shirt pocket.
Great idea.
John
I am not sure I see how this is a better (in any other way than "much more fun to do") solution than glasses - and it may also have some skin/flesh-related sideeffects (strain from being pulled back often/for very long time, tape-rash(?))
I would also think the tape sticking part is very individual (as our skin is different, dryness, sweatyness, etc)
When that is said (and I could be wrong :), for what it is, it is quite an interresting project.
The one thing regarding this vs. glasses is that glasses seem to me to be less intrusive and also very portable (taking them off also turns them off - so to speak).
Having said that. I do not need eye correction (or rather, I might need it, but I dont have/use it) so I am not so familiar with the issues they might have.
Good luck with the improved version!
:)
now all you need is to re-pack it to a nice and smaller kit.
i like how your touch circuit is full of transistors only, not any other electronic component.
does not suck the battery soon? all those transistors?
anyway nice work.
Out of curiosity, how long have you worn this in the "on" position (i.e. how long can you deal with it pulling your skin)? I've found this gets uncomfortable quickly using one's fingers, but tape? Any ideas on what an updated (future commercial) system would use?
http://www.sparkfun.com/products/8782
Basically a tiny device that contracts when voltage is applied.
Seems like the perfect thing if this were ever to be implemented.
The small circuit board and batteries could be located in a box hooked behind the ear (similar to hearing aid) and the tiny flexible strip sits neatly against the skin.