Well, looks like there is something wrong with your eyes, otherwise it would not be common for you to have those feelings. Generally speaking, an eye strain would give rise to painful feelings if you insist on watching TV. Or you have not got a good sleep, or your eyes have got some serious problems. Anyway, here my advice for you is to relax your eyes well and get some eye drops if necessary.
It is hard to tell what caused your eye pain. There are usually many descriptions about eye pain, burning, gritty, sharp and so on. Sometimes it is connected or confused with other symptoms, for example headache. There are many causes to eye pains. If you feel the pain coming from the outer structure of the eye, it might be related to conjunctivitis, corneal abrasion or ulceration, sty, chemical burns or blepharitis. If you feel the eye pain coming from deeper part of eyes, then it might be caused by glaucoma, iritis, optic neuritis, sinusitis and migraines. With so many possibilities, it is really difficult to find out what problem is with your eyes now. If you have been watching TV for a quite long time, I suggest you to take a break. Look at something with further distance to relax the tight muscle. Doing 1-3 minutes of eye exercises would help you relieve your eye strain. If your still feel pain in eyes, and it last for days with some other symptoms, for example, red and watery eyes, blurred vision and etc., I suggest you to see an oculist in case there is any serious problem with your eyes.
When you watch tv, the shining screen will make your eyes feel tired because of the overwork of the visual nerves. You should not watch tv for a long time with little rest. Or else, you may get short sighted. You should protect the eyes carefully which are the very important parts of our body.