Hey, Rembert.
Your optical disc drive (ODD) is likely experiencing a failure of a processing component. The most likely cause here is a laser that is either dirty or has gone bad. I would suggest opening the Macbook to clean the laser and lens of the ODD. If cleaning it doesn't work, you should look into replacing the ODD as a whole, as it would be much simpler and more likely to fix it than just replacing the laser. You can find a guide on how to do so [guide|7583|here|new_window=true]. I hope you found this helpful in some way