Q10. A person cannot simultaneously focus horizontal and vertical lines because eye power differs along perpendicular meridians. The appropriate corrective lens is:
Options

Question

Q10. A person cannot simultaneously focus horizontal and vertical lines because eye power differs along perpendicular meridians. The appropriate corrective lens is:

G1 Physics · Accepted Answer

Step 1: Focusing differs for horizontal and vertical features because the optical system has different powers along two perpendicular meridians. Step 2: This defect is astigmatism; it generally arises from unequal corneal/lens curvature in different meridians. Step 3: A spherical lens adds equal power in all meridians and cannot independently compensate for this difference. Step 4: A cylindrical (or appropriately oriented toric) correcting lens provides meridian-dependent optical power. FINAL A…