What are the primary reasons to prescribe toric soft lenses instead of spherical lenses?

What are the primary reasons to prescribe toric soft lenses instead of spherical lenses?

• A. To correct color vision deficiency.
• B. To reduce cost compared to spherical lenses.
• C. To correct regular astigmatism with stable vision and reduced blur from rotation; indicated when cylindrical error affects vision with spherical lenses.
• D. To increase lens thickness.

Answer: (C)

Toric soft lenses are used when there is regular astigmatism. They have different refractive powers in different meridians, so they can neutralize the uneven focusing that comes with cylindrical error. Because the lens sits on the eye, rotation can misalign those meridional powers and cause blur or ghosting. That’s why toric designs emphasize staying oriented on the eye and often include stabilization features to keep the lens from rotating. The result is stable, sharper vision for someone whose cylindrical (astigmatic) error affects what they see with spherical lenses. Color vision deficiency isn’t addressed by toric lenses, and you wouldn’t choose torics to simply increase thickness or to reduce cost.