There are several different sinus cavities located on your face. Your ethmoid sinuses are located inside your skull, between your eyes and immediately above your nose. Unlike other sinus cavities, which are large, single air-filled spaces, your ethmoid sinuses are small, coin- sized areas that are filled with interconnected bubbles. There are approximately seven to ten of these bubbles, each with its own drainage hole leading to the nose. These bubbles are made up of very thin bone and are lined with a mucous membrane. Ethmoid sinuses are the smallest paranasal sinuses.
Pressure and pain between your eyes is likely the result of infection and mucous build-up in the ethmoid sinuses. What you have to be aware of is that infection and build-up in the ethmoid sinuses can quickly lead to problems in the maxillary and frontal sinuses, as well, causing pain and pressure around the eyes and forehead [source: Avoid Nasal Allergies].