Pin hole test is used for:
PIN HOLE TEST - Completely opaque plastic device with central hole (1mm diameter) - It allows single ray of light that passes through nodal point of eye. - On applying this if vision improves = optical error ( Myopia , Hypermetropia, Astigmatism) if vision do not improves= organic error (macular disease, dense cataract, retinal detachment, retinal diseases) It does not differentiates type of optical error
Optics and Errors of Refraction
Keratoconus
Refractive error
Presbyopia
only Astigmatism
Refractive error