There is no evidence showing that chronic eye strain can cause optic neuritis. And there are many suggestions for preventing optic neuritis. For example, get plenty of healthy exposure to sunlight, which is good for your body to absorb Vitamin D. As Vitamin D is very important for prevent optic neuritis, and taking Vitamin D pills also can helps you prevent optic neuritis.
Optic neuritis is an abnormality that affects the optic nerve. And the precise causes of Optic neuritis is an abnormality that affects the optic nerve is unknown. But Optic neuritis is thought to be a type of autoimmune disorder. And i didn't find any proves that eyestrain is one of the causes to optic neuritis. So, don't worry. But chronic eye strain is really bad for eyes. It may even cause myopia. So, you shall take a regular rest when you work for the sake of your eye health.
Yes, it is possible for you to get optic neuritis due to chronic eye strain. When you get chronic eye strain, your eyes nerves are damaged to some degree which will easily cause the optic neuritis. You could do something to prevent your chronic eye strain. You could use the eyes drops to moisture the eyes. You could also use the warm compress to make your eyes feel comfortable.