B-scan sonography, also known as ophthalmic ultrasound, is a specialized imaging technique used to evaluate the structures within the eye. It is particularly useful when direct visualization of the eye's interior is difficult, such as in cases of dense cataracts or vitreous hemorrhage. B-scan sonography is a valuable tool in ophthalmology, allowing for a detailed assessment of the eye's structures and aiding in treatment planning and monitoring of eye diseases.