Which option is a deposit that may be found on contact lenses?

• A. Protein
• B. Calcium
• C. Lipids
• D. Bacteria

Answer: (A)

Proteins from tears readily stick to contact lens surfaces and gradually build up with wear. This protein film—composed of tear proteins like lysozyme, lactoferrin, and albumin—changes the lens surface, can make it feel less comfortable, and may blur vision. Because tear protein deposition is a common and predictable occurrence with soft lenses, it is the typical type of deposit discussed in lens care.

Calcium deposits are mineral buildups that can form under certain conditions but are less common than protein deposits. Lipids can also accumulate as oily films from tear lipids, and bacteria can colonize lenses as biofilms, but those are not the most characteristic or widespread deposits described for daily wear.