As-salamu alaykum, when i sit down to seek ilm, my eyes suddenly get tired and i become lazy. How to fix this? JazakAllah khayran

Take it as a rule: consistency beats intensity, so fix a daily amount you can actually keep and take a real break every day so that you are able to continue. When the desire to study comes, act on it at once and leave no room for second thoughts, and ask Allah for help, for the Prophet ﷺ used to seek refuge from incapacity and laziness (agreed upon).