Let me preface by stating I'm new to practicing meditation. It has been a week now and do it once for 10-15 minutes everyday in the Lotus Posture.
What I have noticed is that everything is alright when I'm actively focusing on my breath. However, when I stop focusing on the breath & let my mind observe my thoughts or focus on the colourful lights that appear in my vision, the legs and the lower spine feel mild tremors/ vibrations. It isn't exactly uncomfortable – I kind of like it – but I would like to understand what causes it and whether I'm doing something wrong.