The 11820 hand-held, direct illuminating ophthalmoscope from Welch Allyn incorporates an innovative and patented new optical design called Axial PointSource Optics. This technology allows the user of the PanOptic to more easily enter small pupils and provides a field of view of the fundus that's five times larger than ever before achieved with a standard ophthalmoscope in an undilated eye (25° field of view). Direct viewing of the fundus through the PanOptic provides better images of the retinal changes caused by hypertension, diabetic retinopathy, glaucoma, and papilledema to enable clinicians to make these diagnoses earlier. A greater working distance increases comfort for doctor and patient. Compatible with Welch Allyn 3.5V power source handles. Does Not Include Handle.