How can one reconcile studying at university (dentistry) with performing the night vigil (Qiyam al-Layl), knowing that sleeping for less than 8 hours affects concentration?

It is recommended to organize one's daily time for study and worship such that the time before Asr (afternoon prayer) is for lunch and rest, the time after Asr is for revision, and the time between Maghrib (sunset prayer) and Isha (night prayer) is for reading the Qur'an and beneficial books, preferably in the mosque. Then, studying and dinner should be after Isha. One can sleep early to wake up an hour before Fajr (dawn prayer), or wake up an hour after studying. It is also preferred to occupy the time after Fajr with studying or reading, and to be diligent in reciting adhkar (remembrances of Allah) and attending religious lectures.