Why do some people struggle to remain focused while reading

 The reasons could be many and varied.

1. Visual may not be your primary channel for data input. This can be checked out by a VARK Test online. Here is the link: VARK Learning Style Questionnaire
2. Your eye muscles may not be moving in a coordinated fashion. Read this blogpost to know how to correct it. Reflections of Ajit Karve

These are the six related pictures for running the exercise.

3. Go to an ophthalmologist to check your vision.

4. Check out your interest in the subject and its usefulness to you.

That's it.