Arizona State Board Of Optometry Practice Exam

What is the purpose of including diameter on a contact lens prescription?

1. To facilitate communication with patients

2. To ensure proper fitting of the lens

3. To comply with state regulations

4. To record the manufacturing process

The correct answer is: To ensure proper fitting of the lens

The purpose of including the diameter on a contact lens prescription is primarily to ensure proper fitting of the lens. The diameter is a crucial measurement because it directly affects the lens's positioning on the eye. A lens that is too large may cause discomfort and may not sit properly on the cornea, potentially leading to irritation or other complications. Conversely, a lens that is too small may not cover the cornea adequately, which can also lead to discomfort and reduced vision quality. In addition to providing comfort, the correct diameter helps maintain the health of the eye by ensuring that the lens allows adequate oxygen to reach the cornea and facilitates appropriate tear exchange. This is essential for the prevention of complications such as dryness, infection, or corneal damage. Therefore, indicating the proper diameter on a contact lens prescription is integral to achieving an optimal fit, which is a fundamental aspect of successful contact lens wear.