I too fund it hard to focus even with my glasses on and my eyes feel permanently strained and as if they want to just close all the while I'm trying to read articles write ect! Not my sight that hasn't changed appatently according to my optician but my vision goes blurred ect.

I've suffered from this symptom of Fibro as does my mother. However, I recently learned that mine has to do with the muscle tightness of my neck, Occipital muscles, and in the back of the head. The muscle tightness has a direct effect on the blood flow and nerves. I've been doing C1 traction and occipital releases at home, It's made a world of difference. As well as cut the number of headaches down.

I think that we all have certain sensitivities to our environment. I had a problem about 7 years ago, in that if I didn't have sunglasses on I would loose vision in my left eye. It would finally return after 20 to 50 seconds. They ran some tests but of course, nothing showed up. My husband gave me the best birthday present ever, dimmer switch in the bathroom. I wish the whole world would run on one. To bright, dim, too loud, dim, too many people or activists turn it down, to hot or too cold use your blankets. I think that's why I like my bedroom so much. I have complete control of everything. I hate to not be able to be with others, but it takes so much effort to modify
my environment.

Does anyone have to wear sunglasses because the sun is way too bright at times?

I can think of a couple of things you might want to check. First of all is your medications. A couple of the common fibro meds can cause vision issues. Talk to your pharmacist, they are usually the best source of information on medication side effects. Also look at trigger points in certain head/neck muscles that can cause issues. The Trigger Point Therapy Workbook by Clair Davies NCTMB has been helpful for me. WWW.YOUTUBE.COM also has trigger point information. I find that most of us with fibro have "trigger" point issues as well as the infamous "tender" points.