Because your eyes are allergy to pollen. When pollen make your eyes itchy, you can put water to mix chrysanthemum indicum, honeysuckle, horsetail and red flower together. And then boil them. Throw away the solution, just apply the boiled material to your eyes. What you should do is to test which kind of pollen you will be allergy to in hospital. Try your best to get rid of that kind of pollen. When you your eyes itch, you should wear a pair of sunglasses to avoid strong light.
If you get eye itches when you meet pollen, you have a allergy eyes. And this is not a big problems, you can fix the eyes easily. Just use some Counter antihistime eye drop such as zaditor that can help you stop itches. Besides, you can also flush your eyes with saline to help your get rid of excess pollen of your eyes. Or you can try to avoid pollen in your daily life to avoid allergies.
Most of human beings developed an allergy to pollen, maybe you are one of them,especially when it came to eyes, which is the most sensitive part of our body.But,don't worry about it, sheer itchy won't harm that much once you clean it carefully. First of all, use some eye drops to water those hazards out,then close your eyes for several minutes. Keep your grimy hands away from the eyes.