"Eye Blink Switch" is an switch emulator that enables the computer access by the blinking of user.
Just aiming the sensor at the eye will allow the user to control communication devices, toys, or computers. Controls give momentary, timed (1 to 120 seconds), or latched output. Internal circuitry can be set to activate with each eye blink or with every double eye blink to ignore normal eye blinking. An adjustable holder easily mounts to most eyeglass frames or head bands. Eyeglasses not included.
Source: Enabling Devices