eye, eyes +
(Anglo Saxon or Teutonic: in Old English times, eye was eage, which is related to a whole range of words for "eye" in other European languages; including, Greek ophthalmos and Latin oculus [with all of its subsequent derivatives])
A very low intensity light shines into one of the user's eyes. Reflections from the cornea and retina are picked up by a television camera.
As the direction of the person's gaze moves, the relative position of the two reflections changes, and the computer uses this information to determine th area at which the person is looking. The computer then executes the command.
2. A transparent refractive device worn to correct reflection errors in the patient's eyes.
3. A device worn to protect the eyes from glare or particles in the air.
2. Two movable folds that cover the fronts of the eyeballs when closed; formed with fibrous cores (tarsal plates) and the palpebral portions of the orbicularis oculi muscles covered with skin on the superficial, anterior surface and lined with conjunctiva on the deep, posterior surfaces.
Rapid contraction of the contained muscle fibers produces blinking; each has fixed (orbital) and free margins, the latter separated centrally by the puopebral fissure, united at the lateral and medial palpebral commissures, and bearing eyelashes, openings of tarsal and ciliary glands and (medially) the lacrinal puncta.
It magnifies the image made by the objective lens.
2. Pain and fatigue of the eyes, often accompanied by a headache, resulting from prolonged use of the eyes, uncorrected defects of vision, or an imbalance of the eye muscles.