The initial examination of the eye should assess symmetry, conformation, and gross lesions; the eye should be viewed from 2–3 ft (~1 m) away, in good light, and with minimal restraint of the head. The anterior ocular segment and pupillary light reflexes are examined in detail with a strong light and under magnification in a darkened room. Baseline tests like the Schirmer tear test, fluorescein staining, and tonometry (intraocular pressure measurement) may be followed by ancillary tests such as taking corneal and conjunctival cytology and cultures, everting the eyelids for examination, and flushing the nasolacrimal system to evaluate the external parts of the eye, including the anterior segment. Diseases of the vitreous and ocular fundus are evaluated by direct and indirect ophthalmoscopy (usually performed after inducing mydriasis) and vision testing (menace reflex, obstacle course, dazzle reflex, etc).