Why do GP lenses have a decreased fitting inventory?

Why do GP lenses have a decreased fitting inventory?

• A. They are mass produced and dispensed from stock
• B. They require custom fitting and must be ordered
• C. They are cheaper to maintain in stock
• D. They are universally sized and require no fitting

Answer: (B)

Gas-permeable lenses must be tailored to the individual eye; their fit depends on corneal curvature, sagittal height, diameter, and how the edge interacts with the lid. Because of this, clinicians typically use diagnostic trials during a fitting and then place an order for a lens made to that patient’s specific base curve and diameter. That customization means there isn’t a large, ready-to-ship inventory of GP lenses like there is for some other lens types, so the fitting inventory is decreased. In contrast, soft lenses often come in a wide range of stock sizes.

Gas-permeable lenses must be tailored to the individual eye; their fit depends on corneal curvature, sagittal height, diameter, and how the edge interacts with the lid. Because of this, clinicians typically use diagnostic trials during a fitting and then place an order for a lens made to that patient’s specific base curve and diameter. That customization means there isn’t a large, ready-to-ship inventory of GP lenses like there is for some other lens types, so the fitting inventory is decreased. In contrast, soft lenses often come in a wide range of stock sizes.