Newbie: Movement sensor

[Dammi]

Hi there, I've been searching the internet like crazy for something like this when I stumbled upon this site!

I'm trying to make a circuit that detects if a persons eye is blinking or not. I was thinking something on like a sensor mounted on glasses that detect the movement from your eyelids.

Is that possible ? I know where I can get a decent schematic for a proximity sensor, but I'm pretty sure it needs to be a pretty accurate sensor to be able to detect a 0.5mm change in proximity (the eyelid thickness)
So does the same thing apply here for the movement sensor? That hhe movement of the eyelids are to fast and small that you won't be able to detect them?

Any ideas?

 

[Dammi]

And what about using an infrared laser that bounces of your cornea when your eye is open, and when it's closed it won't register ?

Just want to get a feasible idea so I can get started on the circuit without coming to a roadblock!

 

[BrownOut]

Sounds like a difficult task. I'd be tempetd to try a color detector, sense when the color changes. You'd need some optics, filters and light sensors, as well as electronics that detect changing outputs from the sensors. Good luck!

 

[Dammi]

Hmm, so it would be wishfull thinking to try a IR module set up like this:

**broken link removed**

And try to fine tune it so that the current change is measurable when the person closes the eyes ?
I then want to from those different changes make a second circuit, propably with a PIC processor, (I have yet to figure that one out but that won't be a problem) that will notice if the current is low (closed eyelids) for t seconds.

Do you think the current change is so small that it won't be measurable?

 

[BrownOut]

As an amature, I would not radiate the eye with any coherent light. I don't feel as though I know enough to evaluate how safe it is. I would just try to use natural light.

If you're an optometrist, you might have more information about eyeball tissue and how it reacts to a laser.