hello,i want a build a eye goggles that can detect which direction user is looking. need to use optical sensor for this which can differentiate iris region from white scleral region by having different reflected voltages which will be captured by photodiode,source being IR sensor. please suggest a suitable IR transceiver for this purpose. its kind of urgent!
I don't know of anything like this "off the shelf"; most solutions to this problem use some variant of a system like a webcam (some just use hacked webcams!). If you were building such a system, you would probably need to start with a 2D CCD array. You might also be able to get by with a similar sensor as in an optical mouse (which is a really small CCD array - around 64x64 or 96x96 pixels)...
uh, be careful about shining IR directly into people's eyes. IR does not trigger the blink reflex and at close ranges I can see teh intensity from an IR LED being high enough to cause damage. I wouldn't even try doing this because there's literally no way to know if it's safe aside from doing animal studies or something.
Besides, to do this sort of thing you need video and fancy video processing capabilities. I don't see how you could do much with IR detectors.
Besides, to do this sort of thing you need video and fancy video processing capabilities. I don't see how you could do much with IR detectors.
Not really; I think this kind of thing has been experimented with since the 1950s or 60s. There do exist "quadrant photodiode" sensors, which output varying voltage levels (IIRC) from four quadrants; if you could illuminate the eye with an IR LED (pulsed, low levels), then get the voltages out from the detector, then electrically invert the values (I think) - it might work.
That's all you really do with a webcam - except it happens with software filters and other code to determine what direction the gaze is in.
thank you for your replies! CCD cam uses the IR principle. am not sure about the duration for which IR sensor will still be safe but it can be used for eye gaze meausement.it has been tried already,but i need a wavelength matched better component.
http://www.springerlink.com/content/g1863871j1676q5n/