The other tests of visual acuity should be utilized with as much precision as circumstances permit. It is imperative to inspect the anterior chamber of the eye with a bright light placed near the cornea and directed from the temporal to nasal side. A marked deepening of the anterior chamber compared to the normal side, coupled with loss of the normal red reflex when the eye is illuminated and viewed in the axial direction, indicates the presence of a posterior segment penetrating injury which may be hidden and seemingly associated with only minor lid lacerations. These wounds may have actually perforated the lids and penetrated the globe. Gross contamination by dirt or other particulate matter frequently accompanies these injuries.
Corneal lacerations are usually evident by loss of the anterior chamber and distortion of the pupil.
Iris incarceration or prolapse through the wound is common. Scleral lacerations often exhibit extruding, darkly pigmented choroid. However, small perforating wounds and even large scleral lacerations may be obscured by subconjunctival hemorrhage. If the general appearance of the eye is undistorted and careful inspection reveals no site of ocular penetration, gross differences in intraocular tension may be estimated by very gentle digilal palpation. The tips of the index fingers are used in ballottement of the globes through the upper, closed eyelids.