A 31-year-old woman comes to the office due to vision disturbances. The patient is a software developer and works on a computer most of the time. She first noticed blurry vision 2 months ago. Since then, she has had several episodes of blurry and double vision, especially toward the end of the workday. Two days ago, she experienced neck discomfort and had difficulty holding her head up, which resolved after a night's rest. The patient does not use tobacco, alcohol, or illicit drugs. Vital signs are within normal limits. On physical examination, pupils are 3 mm, round, and reactive to light. There is no ptosis, and ocular movements are normal. No neck deformity or tenderness is present. Muscle strength, deep tendon reflexes, and sensation are normal in the bilateral upper and lower extremities. Further evaluation reveals antibodies directed against nicotinic receptors on the motor endplate.