Auto focus Glasses Project

prof_braino

Autofocus glasses

WE saw http://www.geek.com/articles/gadgets/empower-eyeglasses-use-accelerometer-and-lcd-layer-for-electronic-focusing-20110110/

and it was discussed here (thanks erco)
http://forums.parallax.com/showthread.php?128654-1200-Electronic-Glasses

Does anybody know about the electrical focusing mechanism these use? It says "LCD" but instead of forming an image, the LCD changes the lens focal length. Information or links to a kit for exploring this would be appreciated.

Normally, I want the full field of view to be "distance".
For work I want glasses where the entire field of view changed to near range; I look through the center of the lens when working at the computer.

The only time "bottom half" bifocal configuration is useful to me is while driving, but I still want that option.

http://www.superfocus.com/ Offers glasses with manual focus adjustment. There are other methods as well for example

http://en.wikipedia.org/wiki/Joshua_Silver

Any ideas on what would be the best starting platform? (I.E. experince with any of these glasses?)

Any ideas on focusing actuators? (experience with specific micromotors etc?)

Any ideas on simple range finder? We only need to detect the simple near/far threshold, we don't necessarily need millimeter over several meters accuracy. (But it might be fun to bolt a PING sensor to my glasses at some point.

There are enough geezers with failing vision bad as mine for this to be a useful project, I think.

Phil Pilgrim (PhiPi)

Pupilary separation is probably the most reliable indicator of focal distance -- at least for people with sight in both eyes who aren't chronically cross-eyed, suffer from "lazy eye," or are viewing Magic 3D posters. I've always wanted a pair of glasses that would focus based upon actual focal distance, rather than some arbitrary vertical angle of view.

-Phil

prof_braino

Phil Pilgrim (PhiPi) wrote: »

Pupilary separation

How do we measure this ? If we could locate the position of each pupil, the focus could even be maintained at the periphery, instead of just through the dead center directly in the center of the lens.

I was actually thinking of harvesting parts from an autofocus camera, or hacking the image stablization hardware, or using ultrasonic ranging; and testing distance centered in front of the glasses. Reading the position of the pupils would be really handy.

Humanoido

To keep it simple, one could drive the focusing lens with a small servo and do a calibration so a Propeller chip can remember your calibrated eye setting requirements. It could interpolate the other foci. Then at any time the unit could be retrained or tweaked. That would be good for people with eyes that periodically change focus or stick. It would be helpful when taking the drivers eye test and looking through a machine (at a time when you don't want eye glasses to auto-range read distance!).