I will have to follow 1 course at my accademy. One is about openGL the other about VRML.
What would you choose? (course name: virtual reality)
The OpenGL course sounds like it would be much more useful, up-to-date and practical.
From knowing OpenGL you can spread out into a lot of other areas that are closely or somewhat related - games programming, hardware acceleration, user interfaces, visualisation, GPU computing, applications for smartphones and consoles, etc.