My mom cannot wide open her eyes or cannot stare at something for more than a minute; If so, her eyes strain, feel exhausted and blurry. Even she doesn't stare at anything, she still feels soreness sometimes. Her eyes are also afraid of light. When I talk to her, it seems like she always blink her eyes. The above symptoms started from 2013. She did examinations but everything's fine. Also, she has presbyopia since 2013, wearing a lens power of +2.00 to +2.50, but it's common for her age (58).