Did you buy a used bike with a windshield, or did you get a new/old stock bike and they put the windshield on for you?
A windshield needs to be the right size for the rider, if you want to be able to just look over the top edge then it needs to be about the height of your nose.
If you got a used bike the chances of the windshield being the right height for you is hit and miss.
Also it needs to be adjusted, some can slide up or down a bit, and most can be tilted forwards or back, to address head buffeting (feeling like your helmet is in a paint can shaker to the point where your eyeballs are wiggling like jello, and you cannot read road signs).
Read the threads on head buffeting and windshield adjustments, with the warning that what works for one person on their bike might not work for you - its very much a trail and error process, and make adjustments in small steps.
If you give it a shot and nothing seems right, then look into getting fork deflectors (aka lowers). They will effective extend the windshield almost down to the front axle, and get the air flowing up and over your helmet, hopefully throwing it over your head far enough that the break from laminar flow coming off the shield to turbulent chaotic air happens behind your helmet.