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What is Pin hole test is used for: and explain in detail?
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