The invention provides a labeling composition for an intraocular tissue of a living individual, which specifically labels the intraocular tissue without need of an invasive operation such as exposure of an ocular tissue or injection of a staining agent into the ocular tissue or a nerve tissue linking to the ocular tissue, a method of noninvasively labeling an intraocular tissue of a living individual, and a screening method using the labeling composition for the intraocular tissues. The composition contains a compound capable of labeling at least a photoreceptor cell layer of a retina, wherein the compound is a staining compound having a particular structure as a partial structure thereof.
