1. Apparatus for directing a first beam of light energy onto the fundus of an eye and for stabilizing the beam during eye movement, such apparatus comprising means defining an optical path to the fundus for directing a first beam of light energy to be stabilized on the fundus, means for producing and directing at the fundus a tracking beam of light energy, distinct from the first beam, for illuminating a region surrounding a microscopic tissue feature constituting a narrow tracking target extending along a line, angular correction means responsive to a control signal for controllably redirecting the optical path to the fundus, imaging means for focusing light reflected from the fundus through the angular correction means so as to form a fundus image including an image of the tracking target, alignment means in the optical path for aligning the image of the tracking target to place said line in a selected position, and tracking means responsive to movement of the image of the tracking target transverse to said line for developing a control signal representative of eye movement, said control signal being provided to said angular correction means to redirect the optical path so that the first beam is stabilized on the fundus in a fixed position during eye movement.