The following are true:
a. Kirschman's law: the greatest contrast in colour is seen when the luminosity differnece is small
b. Emmbert's law: the perceived size of an object varies in proportion to the distance of the surface on
which it is projected
c. Hering's law: the contraction of a muscle is accompanied by simultaneous and proportional
relaxation of the antagonist
d. Troxler's phenomenon: an image in the periphery of the retina tends to fade or disappear during steady
fixation of another objec
a. Kirschman's law: the greatest contrast in colour is seen when the luminosity differnece is small
b. Emmbert's law: the perceived size of an object varies in proportion to the distance of the surface on
which it is projected
c. Hering's law: the contraction of a muscle is accompanied by simultaneous and proportional
relaxation of the antagonist
d. Troxler's phenomenon: an image in the periphery of the retina tends to fade or disappear during steady
fixation of another objec