Your eyes are like a camera, with different parts that work together to let you see. When the inside part of your eye called the "uvea" gets swollen and inflamed, it's called "uveitis."
Intermediate uveitis is a type of uveitis that happens in the middle part of your eye called the "vitreous," which is like the jelly inside a donut. When this jelly in your eye gets swollen and inflamed, it can cause problems with your vision and can make you feel like you have something in your eye.
Sometimes a doctor can see signs of the inflammation like floaters (little dots floating in your vision) or a haze in your eye when they look at it with a special light.
Intermediate uveitis can happen for different reasons, like infections or problems with your immune system. Sometimes it goes away on its own, but other times it needs treatment with eye drops or medicine. It's important to see an eye doctor (an "ophthalmologist") if you think you might have uveitis, because left untreated, it can cause serious problems with your vision.