Keeler Pocket Ophthalmoscope (2.8v Pocket Ophthalmoscope on AA Battery Handle)   Portable and compact Full diagnostic capability in a compact instrument make the Pocket Ophthalmoscope ideal for the practitioner on the move. Great for domiciliary and ward use or as a back up instrument. Comprehensive lens range Lens range from +20D (+1,2,3,4,6,10,15,20) to –20D (-1,2,3,5,10,15,20) for clear and effortless examination of ocular structures. Pocket clip It has a strong metal clip that can be attached to a pocket and is powered by standard AA batteries. Apertures / Filters: Ideal for domiciliary or ward use An excellent backup instrument Lens range +20D to -20D Brilliant halogen illumination 2.8V battery   Wide Angle Largest beam for largest illuminated area for best general diagnosis. Intermediate A slightly smaller beam also for general diagnosis but where excessive pupilliary reaction encountered. Also for use with children or photophobic patients and for viewing the peripheral retina. Macular Designed specifically for examination of the macular region of the fundus where a larger beam would create excessive pupillary reaction or patient discomfort. Slit Used to diagnose retinal elevations or depressions. (the beam distortion can be demonstrated by shining the slit beam across a pencil lying on a table). Eccentric Fixation A difficult one to describe but essentially used for detecting Eccentric Fixation. Red Free The red free beam is just that i.e. white light with all the red taken out ending up green! When shone in the eye it makes the blood vessels stand out almost black against a grey/green background making detailed examination of the blood vessels much easier.