system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
The duochrome test is for –
assistant
The correct answer is  For subjective refining of sphere following are used:-

(i) The fogging technique 
(ii) Duochrome test 
(iii) Pinhole test