This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Optics and refraction, Subject name: Ophthalmology
Antimicrobial resistance in frequent lens user is due to 
Select and explain. 
A. Biofilm formation, B. Improper handling, C. Unhygienic formation, D. Low potency of antibiotics
A: Biofilm formation
Answer: A: Biofilm formation 
Explanation: The contaminated contact lens provides Pseudomonas aeruginosa an idea site for attachment and biofilm production Continuous contact of the eye to the biofilm-infested lens can lead to serious ocular diseases, such as keratitis (corneal ulcers) The biofilm also prevent effective penetration of the antibiotics, which increase the chances of antibiotic resistance. Reference : AK Khurana Comprehensive Ophthalmology, 6th edition, pg no. 50