The Used Woodlyn refractor incorporates several unique feature when refining the refraction. Choose the option to either rotate the fine sphere refinement knob, or rotate the low sphere disc. Also featured is a unique “Child GuardTM ” which prevents children from inadvertently turning the dials while at the same time serves as a hand rest for the doctor. In addition, the refractor features feather-touch control, a time saving automatically synchronized cross cylinder axis, anti-reflective coatingon lenses.