I’ve noticed lately that my red eared slider is keeping her eyes closed most of the time and opening them only for maximum a minute and then closing them again. She lives in a big tank with a filter, light bulb, and a heater. The light bulb isn’t the issue because I bought her from a place that had this same tank with a bulb just like this one and all the other turtles seemed fine. I take her outside in the sun for uv light. I noticed today that when I took her outside, she opened her eyes and then when i took her back inside, she closed them. So what can be the cause of this unusual behavior?