That is a good sign. 
Evocation is the next step for many people, each time you do magick your sight grows stronger.
Try this method first: structuring wards.
Once you can do that (which is also an exercise in using magickal sight) you can then create an image of Lucifer and evoke him into that image, like evoking a spirit into an idol that represents them.
This should boost your ability to see him and to hear him, and then any pact you make will be much more solid and successful, once you can communicate.