McGreevy and Ellis (1986) separated the effects of perspective distortion and image scaling attributable to FOV-GFOV differences by locally scaling their displays to permit perspective distortion effects while eliminating the effects of magnification and minification
of their target and reference cubes.
If the image scale deviates from 1.0, the result will be a change in optic flow velocity during rotational motion and either image magnification (if GFOV [less than] DFOV) or image minification
(if GFOV [greater than] DFOV) of the scene.
Spectacle lenses provide magnification or minification
, distortions at the lens periphery, unwanted movement of the visual scene when moving the head, and most importantly, an unfamiliar visual world.
Further, the tendency for ocular accommodation to lapse to the resting position with virtual displays has been suggested as the basis of apparent minification
that has also been associated with virtual displays (e.g., Roscoe, 1986), but apparent minification
is probably mediated by accommodative convergence (see Hollins, 1976; Smith, Meehan, & Day, 1992) and other changes in the availability of monocular cues for depth that mediate size constancy (see Meehan, 1993; Meehan & Day, 1995; Meehan, Smith, & Day, 1994).
Contact lenses are very useful for reducing the magnification effect in high plus powers and minification
effect in high minus powers, as well as improving visual field.