I've noticed that the older I get, the less time I can spend playing games in one sitting. It's exactly for this reason... My eyes are getting terribly weak. When I was younger, I could sit in a dark room right in front of the TV for hours. Now, I can last for about an hour or two. It has to be in a soft lit room.
To begin, staring into an electronic device, without the proper room lighting is horrible for your eyes.
If your eyes are becoming terribly weak, I suggest looking towards herbal remedies to at least retain the eye strength you still have. You should research ingesting
Vitamin A in tablet form. It' an unsaturated nutritional organic compound that specifically deals in regulating and maintaining eye health. Specifically, helping in the protein production of
collagen within the connective tissue of your eyes. Vitamin C is also good to take in combination with "A", as they both activate each other within your system.
Growing up, I didn't suffer from weak eye strength. However, I spent many, many hours online that contributed to my eye strain. I learned that herbal remedies don't completely fix the problem. But aid in maintaining your eyesight (with chances for improvement also).