I'm an eye doctor in real life when I'm not quilting. What you've described sounds like eye fatigue. To go from looking at quilts at a distance and then up close (especially when not wearing the correct eyeglass or contact lens prescription) really makes the eyes work more than they should. That can cause headaches, feelings that either one or both eyes are turning more than they should and all other manner of visual discomfort. However, if it happens again, I'd get in for a check up as soon as possible.