Why did the eye protrude out of socket in a thyroid patient?

Hello doctor,

My mother is 51 years old and she had thyroid sometime in the past. There are no signs of it from the last one year. However, she has these bulging eyes all the time, but she can perfectly see everything with her spectacles. I do not really know what happened to her the other day. She was watching her favorite TV show and all of sudden, her right eye popped out of her eye socket and she started shouting. It was such a scary and frightening situation where I and my dad did not know what to do and out of nowhere, my dad suddenly pushed her eye with a little pressure and the eye was back in its position as usual. My mom experienced severe pain after this incident when she was rushed to an Ophthalmologist. The doctor had no clue about the reason for her eye pop out. However, I advised her to go through a few medical tests and the results are yet to come. Meantime, I just want to understand why this happened to her and will this happen regularly and what is the treatment needed to prevent this from happening again. I just do not want to think of any situation where she is alone in the home and the same happens to her. I just want her to be completely cured from this one. Please help me with my query.