I think cereal bars are something easy to grab, but not the healthiest option to go for. A piece of fruit or yogurt is probably better for your energy
I would first try eyedrops, it really helps. Try maybe also sleep mask for eyes during meditation, it’ll give more darkness plus will relax your eyes
I think it depends of which cereal bars exactly. If it's cereals full of suger or covered in chocolate, it's best to not open your morning with them, cause your energy will rise quickly and fall down just as fast.
Maybe for a rushed morning, but not ideal for a habit. It's best to eat something warm, in the morning your digestive system is also still waking up.