What is a common symptom associated with a stye?

A stye, also known as a hordeolum, typically presents as a painful lesion located on the eyelid margin, which is consistent with the symptoms associated with this condition. It occurs due to an infection of the oil glands in the eyelid, leading to localized swelling, tenderness, and redness. This painful bump often makes it uncomfortable for individuals to blink or touch the area around their eyes.

The other options relate to different eye conditions or issues. Blurred vision may indicate refractive errors, cataracts, or other ocular complications but is not a typical symptom of a stye. Diplopia, or double vision, can be caused by issues with eye muscle control or the cranial nerves but is not generally linked to the presence of a stye. Loss of peripheral vision typically suggests conditions affecting the retina or optive pathways and does not correlate with a stye as it primarily affects the superficial layers of the eyelid. Therefore, the defining symptom of a stye is indeed the painful lesion on the eyelid margin.