Tear break-up time will usually decrease with contact lens wear.

Tear break-up time will usually decrease with contact lens wear.

• A. Decrease
• B. Increase
• C. Remain unchanged
• D. Fluctuate

Answer: (A)

Tear break-up time (TBUT) measures how long the tear film remains stable on the corneal surface after a blink. When a contact lens sits on the eye, it disrupts the smooth tear film that normally spreads evenly across the cornea. The lens surface can be uneven or less wetting, and deposits or material from the lens can disturb the lipid and mucin layers that help keep tears stable. This makes the tear film break up more quickly, so TBUT is reduced. In other words, contact lens wear commonly makes the tear film less stable, leading to a shorter TBUT.

Tear break-up time (TBUT) measures how long the tear film remains stable on the corneal surface after a blink. When a contact lens sits on the eye, it disrupts the smooth tear film that normally spreads evenly across the cornea. The lens surface can be uneven or less wetting, and deposits or material from the lens can disturb the lipid and mucin layers that help keep tears stable. This makes the tear film break up more quickly, so TBUT is reduced. In other words, contact lens wear commonly makes the tear film less stable, leading to a shorter TBUT.