Welch Allyn 11720 Guide D'utilisation page 5

The Eye
VITREOUS HUMOR
OUTSIDE
LENS
INSIDE
LENS
ANTERIOR
CORNEA
With the ophthalmoscope 2 inches (5cm) in front of the eye,
the lenses in the rotating wheel produce clear vision at
points indicated in the diagrammatic eye.
The hyperopic or far-sighted eye requires more "plus" sphere
for clear focus and the myopic or
near-sighted eye requires "minus" sphere for clear focus.
RETINA
3