The only suitable lamps are full cutoff lamps. They don't threaten environment and nature and are also economical. Their light  energy is directed towards the floor. The reflection from the floor or other objects doesn't surpass allowed values.

 A good technical solution
would be completely  shaded  ''full cutoff-lamps"  with air filter (the air in lamps contracs and extends because of warming and cooling). A filter would balance  pressure without letting in dust and  insects.

The problem of light pollution will start to be solved when only full  cutoff lamps will be in use.

Translation or lecturetion: Janja Anzicek