The objective methods to measure errors of refraction are all except

The procedure for determining and correcting refractive errors is termed as refraction. It is an a that can only be mastered by practice. The refraction comprises two complementary methods, objective and subjective. OBJECTIVE REFRACTION The objective methods of refraction include: *Retinoscopy *Refractometry and *Keratometry SUBJECTIVE REFRACTION Subjective refraction is meant for finding out the most suitable lenses to be prescribed. It should always be carried out after getting a rough estimate of the refractive error by the objective refraction as described above. The proper subjective refraction includes three steps: I. Subjective verification of refraction II. Subjective refinement of refraction, and III. Subjective binocular balancing Subjective binocular balancing: The final step in the subjective refraction is binocular balancing--a process sometimes known as 'equalizing the accommodative effo' or 'equalization of vision'. This allows both eyes to have the retinal image simultaneously in focus. Reference : Khurana Comprehensive Ophthalmology; 4th edition ; Pages: 547, 548, 554, 557.