But other than the pressure in the eye, there is unexpected difference between people who tend to have glaucoma and people who don’t tend to have glaucoma.
That is whether or not you have nearsightedness.
People who have nearsightedness tend to have glaucoma and people who don’t have nearsightedness don’t tend to have glaucoma. Nearsighted people have glaucoma with a high probability. Normal eye’s shape is sphere but nearsighted eye’s shape is oval. Because of the shape, the part of the eye near the optic nerve is pulled, causing tension to the optic nerve like the pressure in the eye is high (Fig. 1).
Glaucoma is unnoticeable because in the case that one eye has normal sight and another eye has narrowed sight, the brain combines the images as if the image is seen clearly.