Since you still have not explained how you recognize fatigue but rather how you appear to try to trick you mind to not experience fatigue, I'll explain some of my tricks.

First, I cannot read a paragraph with more than 5 or 6 lines before a paragraph break. I can't find the start of the next line and there is just too much text to try to grasp. Long line lengths are also a struggle. Besides convergence insufficiency, I also have anisiekonia. The right eye sees an image that is wider that it is tall so my eyes have even more struggle working together. I've lived with convergence insufficiency since I was 10 so I just deal with it. The anisiekonia is the result of cataract surgery.

On top of that, I have PVD in both eyes. Posterior Vitreous Detachment is when the vitreous humor, the gelatin like substance in the eye, develops folds in it. It is like looking through a spiderweb. Think of looking through a bowl of jello that has been shaken and is full of cracks.

I have learned to change activities, especially what I am looking at if: I find I need to reread a line of text. I struggle to scan and find things. I have even more struggle than usual to find the start of the next line.

When this happens, I don't push through. I switch to a different task on a different screen. I would change from a computer screen with text and such to a TV screen with no or limited text and watch a show, usually informative like Discovery Channel. I might be able to go back to the computer screen in 10 to 20 minutes. That was my life for about 2 years as I figured this out.

Now, If I must continue to read the screen when I know I have fatigued, I will change the image size, larger text/font, make the window narrower so the line lengths are shorter.

Learning how to moderate the various stimulation and to accept that I could not push through made my life much better.

I still have things I just cannot endure but most things I can handle by moderating my exposure.

I could not watch TV unless I had headphones on for the sound track. Otherwise, the processing load of the sound reflecting in the room was too much, especially with sports. I also would DVR record sports so I could fast forward through the over-stimulating parts.

I also learned that some media are just not possible due to too much stimulation.

Things got much better after learning how to not strain and fatigue my brain.

I did a lot of task switching. I still do but can stay with a task for much longer before fatiguing.