B-Scan Ultrasonography is a noninvasive test for diagnosing problems and conditions of the posterior portion or back of the eye. Conditions such as retinal detachment, ocular trauma, eye tumors such as choroidal melanoma and retinoblastoma and vitreous degeneration can be accurately evaluated with this testing even when direct visualization of the intraocular structures is difficult or impossible. Situations that prevent normal examination might include lid problems, dense cataracts, corneal scars and vitreous opacities or hemorrhages. In such cases, diagnostic B-scan ultrasound can accurately image intraocular structures and give valuable information on the internal structures of the eye.