M19. 4 weeks ago started having slight double vision. Both eyes. Letters on tv slightly raisedlooks like ghost. Also see rays of light. Optometrist said I have astigmatism in one eye. Causes? 20/20 vis.

Ophthalmologist. Try to figure out if your double vision gets better if you close one eye. An ophthalmologist (as opposed to an optometrist) may be better able to sort this out for you.
Does double vision. Remain when on eye is closed? If so the either an astigmatism or surface eye dryness can be the cause. If the double vision goes away when one eye. Is closed you will have to see an ophthalmologist to evaluate this.