Ophthalmoscopes are handheld devices that illuminate and magnify the eye's interior (fundus) for retinal examination. Direct ophthalmoscopes provide 15x magnification through interchangeable lenses (+/- diopters) and apertures (small/large spot, red-free filter, cobweb); examiners align red reflex from 15° temporal angle, approaching to 2 inches for optic disc, vessels, macula visualization—detecting glaucoma cupping, diabetic retinopathy hemorrhages, or papilledema. Indirect (head-mounted) offer wider peripheral views (2-5x) with handheld lenses for retinal tears. Used in routine exams for hypertension/diabetes screening; darken room, dilate pupils for clarity.