What is it when your left eyeball is swollen for no reason?

A swollen left eyeball can be caused by various factors, including Allergies, infections, or injuries. Conditions such as conjunctivitis (pink eye), styes, or even insect bites can lead to swelling. If there's no apparent reason and the swelling persists or is accompanied by pain, vision changes, or discharge, it's important to seek medical attention to determine the underlying cause.