is detected state 540 results from a timeout which triggers a power down device state 550 this corresponds to resetting of flip flops 140 and 115 if fig1 state 550 transitions back to power save state 300 shown in fig3 and more specifically to state 460 within that state fig6 is a flow chart of a one power control process used as part of the invention eyetracker 290 shown in fig2 b is utilized to control the illumination of images on the display 220 how this is done is shown in fig6 the eyetracker outputs are processed to distinguish four conditions shown in fig6 namely 1 whether the eyes are fixed at a point on the screen 3 whether the eyes are approaching the screen from a position off the screen and these four cases are distinguished by seperate processing branches shown in fig6 when the eyetracker determines that the eyes are fixed on the screen case 1 610 obtains and the display intensity is set at normal illumination 615 in case number 2 620 when the eyes move from the screen to a point off the screen a time interval of preferably 1 10 of a second 625 is set if that time expires without the eyes returning to the screen the screen will slowly fade the display intensity to black 626 in the embodiment shown in fig6 once the eyes have been off the screen for a period of time greater than the time set in item 625 cases 3 and 4 are treated identically that is whether the eyes are approaching the screen or moving across the screen without fixing on the screen the display intensity will resume normal illumination as quickly as possible normal illumination will thus continue until such time as the.