Most units offer testing for both near vision (typically at 40cm) and distance vision (6m), though research suggests it is most effective for near vision assessments.
It identifies the "aligning prism" (associated phoria) required to neutralize subjective disparity, making it a direct guide for prescribing therapeutic prisms. buy mallett unit
A significant body of research supports its use in alleviating asthenopic symptoms (eye strain). Buying Guide: Pricing and Availability Most units offer testing for both near vision