What is the CCMS method primarily used for?

The CCMS (Clean Catch Midstream Specimen) method is primarily used for obtaining urine samples, particularly in a way that minimizes contamination from bacteria or substances found on the skin or in the genital area. While the correct answer may relate to collecting samples, the primary purpose of the CCMS method specifically involves urine collection rather than blood samples. This method is crucial when a healthcare provider needs to analyze the urine for various medical conditions, such as urinary tract infections.

The other options mentioned, such as blood sampling and conducting tests for vision or respiratory function, do not pertain to the CCMS method. Blood samples are typically acquired using different venipuncture techniques, while urinalysis is specifically associated with the collection method indicating it is indeed suited for urine testing.