What typically indicates the presence of astigmatism in a patient's prescription?

The presence of astigmatism in a patient's prescription is typically indicated by the inclusion of sphere, cylinder, and axis measurements. Astigmatism occurs when the cornea or lens has an irregular shape, leading to blurred or distorted vision. To correct this, the prescription must include the spherical portion, which addresses myopia (nearsightedness) or hyperopia (farsightedness), as well as the cylindrical portion that corrects for the astigmatic error. The axis measurement specifies the orientation of the cylinder correction needed.

In a complete eyeglass prescription that includes astigmatism, the cylinder measurement indicates the degree of astigmatism, while the axis specifies the direction of the correction needed. Thus, the presence of all three components — sphere, cylinder, and axis — clearly indicates astigmatism and enables the optometrist or ophthalmologist to prescribe the appropriate lenses to correct for this visual distortion.

The other options do not provide a comprehensive indication of astigmatism. For example, a prescription that contains plus sphere power alone does not account for the additional correction needed for astigmatism. Similarly, ADD power is typically used in multifocal prescriptions for presbyopia and does not imply astig