Which statement accurately describes the main forms of aspheric GP lenses?

Which statement accurately describes the main forms of aspheric GP lenses?

• A. Spherical aspheric
• B. Back surface aspheric
• C. Front surface aspheric
• D. Both back surface and front surface aspheric

Answer: (D)

Aspheric GP lenses can be shaped on either surface, and each surface serves a different purpose. The back surface is the one that sits on the cornea, so making it aspheric helps it match the corneal curvature more closely, improving fit, movement, and comfort. The front surface is the optical face that determines how light enters the eye, so an aspheric front surface can reduce spherical aberration and improve image quality. Some designs use an aspheric contour on the back surface, others on the front surface, and some use both surfaces aspheric to combine fitting precision with optical quality. Therefore, the most complete description is that aspheric GP lenses can involve the back surface, the front surface, or both.

Aspheric GP lenses can be shaped on either surface, and each surface serves a different purpose. The back surface is the one that sits on the cornea, so making it aspheric helps it match the corneal curvature more closely, improving fit, movement, and comfort. The front surface is the optical face that determines how light enters the eye, so an aspheric front surface can reduce spherical aberration and improve image quality. Some designs use an aspheric contour on the back surface, others on the front surface, and some use both surfaces aspheric to combine fitting precision with optical quality. Therefore, the most complete description is that aspheric GP lenses can involve the back surface, the front surface, or both.