If you have a foreign body sensation in my eyes, perhaps there are particle on the surface of your eyes, you can use a mirror and blink your eyes to see if there are some particle in your eyes.
In fact, aside from the above reasons, dry eyes and conjunctivitis or other inflammatory conditions can also cause you feel foreign body sensation in your eyes. If so, you shall ask help from eye doctor.
First, I will tell you when some foreign bodies enter into your eyes, what should you do? You should close your eyes for a while, and then gently pull open your upper eyelid. In general, the foreign body can get out along with your tears. If you turn your eyelids, but not find foreign body, the foreign body may be in the cornea, and you should go to the hospital and have a treatment. But if it is not the foreign body, in general, it may be conjunctivitis or dry eye. You can drip anti-inflammatory eye drops, if it does not help, you should go to the hospital.
I am wondering if there is something going into your eyes make you feel so uncomfortable,you can find someone to help you to make sure it. If you still feel very sensitive, you'd better go to see a doctor. One month ago, I happened the same experience as you, and I went to see a doctor, the doctor told me just because a little knot in my eyes, he gave me some medicine and asked me to eat as his prescription. Some days later, i was recovered, and my eyes was no longer pain and went back to normal.
This symptom usually originates from the cornea, which is the clear tissue covering the front of the eye. Pain, redness, tearing, sensitivity to light, and blurred vision are the most common reactions when you get the disease. The cause of "foreigh body sensation" may include: Bacterial conjunctivitis, Blepharitis, Dry Eye, Vernal keratoconjunctivitis, Corneal abrasion, Corneal dystrophy and so on. If you feel it serious, do not touch or rub your eyes which may cause seriou injury to your eyes and immediately rush to an Opthalmologist to seek for help.