Final answer:
Astigmatism is the medical term for an eyeball shaped like a rugby ball, which is a refractive error that can cause blurry or distorted vision.
Step-by-step explanation:
The medical term for an eyeball shaped like a rugby ball is astigmatism. This refractive error occurs when the curvature of the eye's cornea or lens is irregular, making the cornea more oval-shaped like a rugby ball rather than perfectly spherical. This results in blurry or distorted vision since the light entering the eye is not focused correctly on the retina. Astigmatism can be corrected with glasses or contact lenses that compensate for the irregular curvature.