It is true that flying high can cause high eye pressure. But the effect of this change remains a subject in scientific realm. The eye pressure is generated by production and flow of eye fluids. When the fluid in the eyes is abundant, or the drainage is blocked, the eye pressure will increase. A study has shown that the eye pressure varies from one altitude to another, and it will be back to normal after several days. If one remains in high altitudes, his/her eye pressure will also become normal. If one has ocular hypertension such as glaucoma, he/she should consult an ophthalmologist before flying. For patients in the vitrectomy recovery, the pressure change is dangerous for the healing. So they must get the approval from their ophthalmologist first.
Well, of course yes, flying can lead to high eye pressure because of the gravity. Maybe you feel strange about it, but it actually occurs. First, you should know that when you take the fly, there will have gravity, and it can give you a kind of pressure on your eyes, when it takes off. In that way, high eye pressure will occur to your eyes. And eye strain can be another one. And for some people whose eyes are sensitive, it is very normal to have red eyes or headache when they have flying, because of the high eye pressure. Especially for some people who have taken some eye surgery, it can be dangerous to take a plane. So just be careful about it.
Yes, flying will cause high eye pressure. Thus you should not wear the contact lenses when you fly. If you have the high eye pressure, I suggest you not fly which may make the situation get worse. Or else, you take some medicine to make the eye pressure get stable. Eye is the very important part for the whole body which you need to take great notice of and protect it well.