A stye or chalazion can cause eye pain:
Styes and chalazia are among the most common eye problems.
A stye or hordeolum is a small bump that forms on the outer edge of the eyelid. It develops when an oil gland in the eye becomes blocked and clogged, causing a small, localized infection. A stye may be very painful or sensitive to the touch.
A chalazion is similar in appearance to a stye, but it is internal to the back of the eyelid. Like styes, chalazia develop as a result of a blocked oil gland in the eye. Unlike styes, chalazia are usually not due to an infection and do not typically cause pain unless they grow very large.
Styes often clear on their own. Applying warm compresses to the affected eye can help drain the stye and speed up the healing. Very large or painful styes may require antibiotic treatment.
Warm compresses can also help clear a chalazion. However, an eye doctor may need to surgically remove a persistent chalazion or one that grows very large.