What Does A Pressure Feeling Behind The Eye Suggest?

hi I was having pressure kind of feeling behind my eyes i went to eyes specialist and all eyes test are completely fine still i have this pressure and heaviness kind of feeling inside my brain (back side) from past 4-5 days and this is feeling is continous I have slept fine and completed my rest 9hours sleep every night still whenever i wake up i have this heaviness inside my brain no other symptoms yet discovered only little very little stiffness on back side of my neck