Ptosis of the eyelids is a common condition with a myriad of causes. Its management depends on the underlying cause, which can be challenging to diagnose in some cases. Current diagnosis methods include serum antibodies, tensilon test, and electromyography (EMG). Each has its own set of limitations such as invasiveness and lack of sensitivity. To overcome these limitations, we have developed a Portable Realtime Infrared Lids, Iris and Blink (PRILIB) monitoring system, with a long-term goal to improve clinical diagnosis of ptosis. In this paper, we present the algorithms to detect and analyze eye parameters and report experimental results. From experiments conducted on normal volunteers and myasthenic patients, we found 1. Partial blinks happen when Ocular Myasthenia Gravis (OMG) patients are tired or engaged in an activity; 2. Blink rate is significantly higher for OMG patients due to failure to blink fully; 3. There are noticeably more fluctuations of palpebral aperture of OMG patients due to rising and falling of the eyelid height. These experimental findings suggest new diagnostic features for OMG patients and have implications for disease management.