A vitrector that includes an adjustable illumination aperture is described. The vitrector may include a probe and a light sleeve assembly extending along and substantially surrounding the probe. The light sleeve assembly may include a plurality of optical fibers. At least a portion of the optical fibers are operable to provide illumination so as to define an illumination aperture about the vitrectomy probe. A portion of the optical fibers may be encapsulated. The light sleeve assembly may be adjustable along a length of the probe, providing adjustment of the illumination aperture to increase or decrease an area of illumination provided thereby.