It is very common for diabetic patients to complain of photophobia (discomfort or pain to the eyes due to light exposure). There are many reasons, the most important one is that it is always very sunny here. The amount of sunlight is much higher than, for instance, in Europe, so it is also more difficult to move around if you are more sensitive to light.
Other reasons are related to the eye conditions, like for example, cataract or retinopathy. So if somebody has problems in the retina or had an eye operation it is normal for them to be more sensitive to light. This is why we always use intraocular lenses with special UV filter to protect the retina when we operate diabetic patients and, of course, everybody should wear sunglasses when outdoors.