«Near Vision Ready Made Spectacles» (RMS), also called «Over The Counter Spectacles» (OTC), are described by Industry Standards like British Standards BS EN 14139:2002 and ISO 16034:2002. The problems sometimes induced by binocular RMS are induced vertical prismatic effect and horisontal prismatic effect, caused by the difference in interpupillary distance which should be smaller for reading glasses than for distance. Such innacuracies in RMS can cause eye stress (astenopia) or headache.
These are problems that are non-existing for a monocular solution, which are also not for long term continuous use. Just when you need it!