By Argyll Cyrus Geducos ISTANBUL, Turkey---President Duterte revealed Saturday that he is suffering from a condition called myasthenia gravis which weakens the muscles in his eyes. President Rodrigo Roa Duterte delivers his speech during his meeting with the Filipino community at the Exhibition of Achievements of National Economy (VDNH) in Moscow on October 5, 2019. ROBINSON NIÑAL JR./PRESIDENTIAL PHOTO/ MANILA BULLETIN During a meeting with members of the Filipino community in Russia Saturday evening, the President said his condition affects the muscles in his eyes. "Ganun ako eh. May talent ako, magtingin ako sa'yo, 'yung isang mata ko bumaba. Kita mo maliit 'yung isa, tingnan mo. O 'di maliit. O 'yun. Nag --- nagsasariling biyahe 'yan (I have this talent that when I look at you, my other eye looks down. See, the other one's smaller. It goes on its own way)," he jested. "Actually my --- that's myasthenia gravis. It's a nerve malfunction. I got it from my --- exactly from my grandfather. So, I believe really in genetics. Kung anong sa kanya, nakuha ko eh (I got what he has)," he added. The National Institute of Neurological Diseases and Stroke defined myasthenia gravis as a chronic autoimmune neuromuscular disease that causes weakness in the skeletal muscles, which are responsible for breathing and moving parts of the body, including the arms and legs. It added that the condition causes muscle weakness that worsens after periods of activity and improves after periods of rest. Certain muscles such as those that control eye and eyelid movement, facial expression, chewing, talking, and swallowing are often (but not always) involved in the disorder. The muscles that control breathing and neck and limb movements may also be affected. Myasthenia gravis is the latest medical condition that afflicts the 74-year-old President. Last year, the discoloration of Duterte's face was once the subject of speculations which was followed by a cancer scare.