Which type of disinfection is most commonly used?

• A. Ultraviolet
• B. Chemical
• C. Heat
• D. Radiation

Answer: (B)

In clinical practice, selecting a disinfection method hinges on effectiveness across many microbes, speed, cost, and what can be safely used on the equipment. Chemical disinfection is most commonly used because it reliably cleans a wide range of surfaces and noncritical instruments, is typically quick and affordable, and is compatible with most ophthalmic equipment when used with proper contact time.

Ultraviolet disinfection requires direct exposure and doesn’t reach shaded areas, so it can’t reliably disinfect complex equipment on its own. Heat disinfection (and sterilization) is highly effective but not all items tolerate high temperatures, limiting its universal use in a typical clinic. Radiation methods, while powerful, are expensive and impractical for routine everyday disinfection. For these reasons, chemical disinfection remains the standard choice.