Assalamu Alaikum, Areum.
In Islam, the guidelines on lowering the gaze are intended to maintain modesty and prevent inappropriate thoughts or actions. However, when it comes to educational settings, the situation can be more nuanced.
If you are looking at your male teachers purely for the purpose of understanding the lecture and without any ill intentions or desires, it is generally not considered sinful. The primary goal here is education, and as long as you maintain your modesty and respect, you are fulfilling your duty as a student.
Many scholars agree that in such contexts, the necessity of learning and understanding the material can justify looking at the teacher. It’s similar to how you would interact with a Quran Teacher when learning Quranic studies; the focus is on gaining knowledge and understanding.
If you still feel uncertain, it may be helpful to seek advice from a trusted religious scholar who can provide guidance specific to your situation.
Remember, intentions play a crucial role in Islam. As long as your intention is to learn and not to derive any inappropriate thoughts, you are acting within the bounds of Islamic teachings.