such a way that the eye 12 must change its accommodation so as to bring the image into focus this causes the field of view of the eye 12 to be fully occupied with an up close image if the cameraman 39 s eye 36 changes to a long view of the scene 32 as explained above the image 54 fig3 fills the screen 28 because the control signal on the line 26 causes the optic 24 to expand the extent to which the screen 28 is filled by imagery at the same time the signal on the line 64 causes the optic 60 to expand the field of view provided for the eye 12 e g by reducing its magnification or increasing its focal length the eye 12 changes its accommodation accordingly in other words when the control signal on the line 26 causes the optic 24 to increase the extent to which the screen 28 is filled by imagery as in fig3 the signal on the line 64 causes the optic 60 to increase the field of view provided for the eye 12 even further e g by decreasing its magnification even more fig6 shows a variation of fig1 where instead of sensing the cameraman 39 s eye the eye of the user is sensed as shown an eye sensor 70 senses an eye of a user for instance by sensing accommodation a control signal having a magnitude indicative thereof is provided on a line 74 to a control 76 which provides it.