Four-year-old baby’s eyes blinking all the time may be caused by over-fatigue, allergic conjunctivitis, inverted eyelashes and other reasons. 1. Overfatigue: If a four-year-old child looks at cell phones, TV and other electronic products for a long time, eye fatigue may occur, causing the child to blink frequently, and at the same time, the eyes will appear to be swollen and painful symptoms. 2. Allergic conjunctivitis: If a four-year-old baby’s eyes are always blinking and accompanied by itching, eye discharge and other symptoms, it may be caused by allergic conjunctivitis, which can also be accompanied by foreign body sensation, burning sensation, photophobia, tearing and other symptoms. 3. Inverted eyelashes: Inverted eyelashes can cause irritation to the cornea and the conjunctiva, triggering eye pain, redness and photophobia. When the eyelashes for a long time to cause eye irritation, will also trigger the baby always want to blink performance. Parents are advised to take their babies to the ophthalmology department of a regular hospital to determine the cause of the problem and follow the doctor’s instructions.