What type of astigmatism is represented by the RX Plano +1.00 x020?

The prescription RX Plano +1.00 x020 indicates that there is no spherical component (Plano means there is no refractive error requiring correction in that meridian) and a +1.00 cylinder at an axis of 20 degrees. This setup characterizes simple hyperopic astigmatism.

In this case, the plano indicates that one meridian (the one at 20 degrees) does not require additional power (is emmetropic), while the other meridian (perpendicular to the 20-degree axis) is hyperopic (requires +1.00 correction). Thus, the eye has only one meridian that is hyperopic, and the other is normal, which aligns with the definition of simple hyperopic astigmatism.

Differentiating among other types of astigmatism can help clarify this further. For example, compound hyperopic astigmatism would involve two positive cylinder values, while mixed astigmatism would present with one positive and one negative cylinder value. Therefore, understanding the components of the prescription makes it clear why the correct identification is simple hyperopic astigmatism.