To clean the internal lenses of a refractor, you must:

• A. Clean the exterior lenses only
• B. Wipe with household solvent
• C. Return the refractor to the manufacturer
• D. Disassemble the refractor and clean each part

Answer: (C)

Internal lenses are part of the instrument’s precise optical system and have coatings that can be damaged by improper cleaning. Only trained technicians with the proper tools and authorized solvents can safely disassemble, clean, inspect for wear or contamination, reassemble, and realign the optics. Attempting to do it yourself risks scratching or coating damage, misalignment, and voiding the instrument’s warranty.

Exterior cleaning alone won’t address dirt or contaminants inside the optical path, and household solvents can harm coatings or materials. Disassembling and cleaning every part without the right procedures can compromise safety and performance. Returning the refractor to the manufacturer ensures proper cleaning, inspection, and recalibration by qualified technicians.