I have a Stratoliner with the tall windshield not a 950. But I think the idea is the same. With both my V Star 1100 and Stratoliner the air behind the windshield would start to move around to the point that it moved my glasses when I get above about 65 MPH. I felt the air coming in under the windshield was turning up and causing turbulence behind the windshield. In my case on both bikes lower wind deflectors just below the windshield solved the problem.
There are other approaches. I saw where person solved the problem by tipping the windshield forward or back more. Some bikes have a vent around the handlebars level to let in air. Examples BMW 1200 LT, Yamaha FRX. Some Goldwings.
Each case is different, Try getting in a safe spot and hold your hand low and try to see where the wind is comming from. Move your feet forward and rearward, trying to change air flow. Once you know where your air is comming from then you can deal with it. I heard one person say air was comming over his helmet and creating a turbulence behind his head shaking he helmet. I don't believe I have had this problem. Maybe I don't go fast enough.