Back toric GP lenses are commonly used for which type of corneal astigmatism?

Back toric GP lenses are commonly used for which type of corneal astigmatism?

• A. WTR
• B. ATR
• C. Oblique
• D. No astigmatism

Answer: (B)

Back-surface toric GP lenses correct corneal astigmatism by having a toric curvature on the lens’ posterior surface that matches the cornea’s cylinder. This design is especially effective when the cornea has against-the-rule astigmatism, where the steep meridian runs horizontally. The posterior toricity aligns with that horizontal steepness, and lid forces help keep the lens oriented steadily, providing reliable, stable vision. If there’s no astigmatism, a spherical GP would be chosen instead.

Back-surface toric GP lenses correct corneal astigmatism by having a toric curvature on the lens’ posterior surface that matches the cornea’s cylinder. This design is especially effective when the cornea has against-the-rule astigmatism, where the steep meridian runs horizontally. The posterior toricity aligns with that horizontal steepness, and lid forces help keep the lens oriented steadily, providing reliable, stable vision. If there’s no astigmatism, a spherical GP would be chosen instead.