Final answer:
The muscles affected by the patient's condition are Levator palpebrae superioris and Superior tarsal muscle.
Step-by-step explanation:
The muscles affected by the patient's condition are Levator palpebrae superioris and Superior tarsal muscle.
Myasthenia gravis is an autoimmune disorder that causes muscle weakness. In this case, the patient's eyelids are drooping due to the blockage of acetylcholine receptors on the neuromuscular junction's motor endplate. The muscles responsible for raising the eyelids, the Levator palpebrae superioris and the Superior tarsal muscle, are affected by this condition.