Retinoscope
Retinoscope works on a principle called Foucault's principle. Basically it indicates that the examiner should simulate the infinity to obtain the correct refractive power. Hence a power corresponding to the working distance is subtracted from the gross retinoscope value.
Static retinoscopy is performed when the patient has relaxed accommodative status viewing a distance target; dynamic retinoscopy is performed when the patient has active accommodation from viewing a near target.
