Ophthalmologic signs are the most often presenting symptoms of patients with myasthenia gravis (MG), most common being ptosis. However, ptosis may be caused by a variety of non-myasthenic disorders; hence, the distinction between them and myasthenic ptosis is critical. A battery of diagnostic tests are available to establish the diagnosis of MG, all having their pros and cons, some being life threatening. The authors present a case of 40-year-old male who presented to them with progressive weakness and double vision in which they were successful in narrowing the differentials to myasthenia by performing a simple bed side test.