Here's a very interesting hypothesis I found in Dr Maskin's brilliant book, Reversing Dry Eye Syndrome.

Referred eye pain (occipital neuralgia)

He suggests that occipital tenderness, caused by tense muscles at the base of the skull and neck, can cause pain in the eyes.

Further

Greater occipital neuralgia (greater occipital nerve) arises from the occiput and may radiate anterior to the ipsilateral eye. Local anesthetic injection of the greater occipital nerve may relieve the pain. [Source]

Posterior occipital neuralgia is pain originating from the base of your skull that often wraps around to the front of the head and behind the eyes. The pain is due to inflamed or damaged occipital nerves in your neck. Pain can be severe and chronic and can affect one or both sides of your head.[Source]

This pain can be effectively diagnosed with an injection of lidocaine, a local anaesthetic. 

Treatment: massage and heat application.

Once the underlying causes of your pain are determined, in most cases your ophthalmologist (Eye M.D.) will prescribe anti-inflammatory medication to reduce inflammation, muscle relaxants to stop spasms, physical therapy, massage, heat, and rest.

Patients usually recover fully from posterior occipital neuralgia once the pain has subsided and any damage to the nerves has been reduced or repaired. [Source]

FROM THE INTERNET

1) Detailed description:

So many of my patients present with vague headaches and pain around the eyes. Well, it usually originates at the back of the neck. There is a twig of the trigeminal nerve (the sensory nerve of the had and neck) that connects to the tendon at the base of the skull. Lifting, cradling the phone, straining, grimacing during an examination, whiplash and even emotional tension can cause a knot at the base of the skull on either side of the cervical spine. This knot causes the eye pain and headaches and only needs to be recognized to be relieved.

If you have chronic sharp or dull pain that seems to arise deep in the eye, think Occipital Neuralgia, which is what this syndrome is called. You may know it as a tension headache. The pain can actually be referred pain to the forehead, jaw, ear or entire head. Many doctors and dentists don’t realize the remote source of the pain so you must be aware of this common syndrome. You can actually feel the knot in the neck and in the shoulder; then press firmly with two fingers. This will elicit neck discomfort and often exacerbate your eye pain. The ultimate treatment is deep tissue massage and not chiropractic or physical therapy.

I would suspect that each of you has experienced a tension headache. Now you know what to do…get a massage. [Source]

2) Neck massage

Your neck muscles go to the top of your head for its movements. The nerves for your eyes go to the back of your head, right past those muscles. When the muscles are tight they press into the nerves to cause pain to be felt on the back of the eyeball.

To get rid of both these problems you have to free up the muscles in your neck. Put your hands alongside your head so your thumbs are on the front of the muscle under your ear and your fingers are on the back of the muscle behind your neck. Squeeze your thumb and fingers together and hold.

Relax your body. When your fingers and thumb touch, about two minutes, slowly lower your head as far as you can, release the pressure but hold your neck lowered for another 30 seconds. 

For best results relax your body first by taking a deep breath and exhaling then remain this relaxed.

3) Facial Yoga

Details here: http://www.antiaginghacks.com/yoga-secrets-to-an-ageless-face/

4) Avoid tight neck:

Stiff neck and shoulder muscles will reduce blood flow to your head and eyes, which can damage the eyes. [Source]

5) Stress can cause dry eyes

Stress can cause changes in your body, as well as your emotions. Some of the common symptoms include dry eyes [Source]