Duochrome test is used for
Refining the sphere : The spherical correction is refined after refining the cylinder power and axis . It is done by following tests : Fogging technique Duochrome test Pin-hole test Reference : A.K.Khurana; 6th edition; Page no: 578
Colour blindness
Cylindrical axis
Spherical axis
Astigmatism
Optics and refraction