Let's take the glaucoma question first. Assuming that your grandmother's eye pressure is well controlled, flying on a commercial aircraft should not pose any adverse risk to her vision.

Regarding her abdominal aortic aneurysm, the answer is not so straightforward. Independent of whether she should fly, she first needs to know the size of the aneurysm.

The normal width of the aorta is a little less than one inch (2.5 centimeters). As we age, the artery tends to expand a little. An abdominal aortic aneurysm is a dilatation of that portion of the aorta that resides within the belly. If the diameter increases above 3 centimeters, the person is said to have an abdominal aortic aneurysm.

The size of an aneurysm correlates closely to the risk of rupture. Relatively small abdominal aortic aneurysms of 3 to 4 centimeters are quite common. An aneurysm of less than 4 centimeters has a low risk of rupture. Aneurysms over 5.5 centimeters in diameter have a high risk of rupture. Emergency surgery to repair a ruptured abdominal aortic aneurysm carries a much higher risk of death than a scheduled repair of the aneurysm.

Flying would not cause the aneurysm to change in size. However, if your grandmother was very unlucky and had the aneurysm rupture in flight, there would likely be a delay in getting the emergency care she would need.

If the aneurysm is less than 4 centimeters, her doctor would probably say it is safe for her to fly. If it is wider than 4 centimeters, she should check with her doctor before getting on board.