Insufficient blood supply to the eye according to the severity of different, the performance of the symptoms are also different, the details are as follows: 1, the more common is a transient black blindness, the onset of the onset is characterized by a sudden and painless loss of vision, usually lasts for a few seconds to a few minutes, after the onset of the visual acuity can be restored to normal. 2, if the time is relatively long, the symptoms of insufficient blood supply will affect the fundus of the eye, the emergence of arterial thinning, and hemorrhage in the retina, If the symptoms of insufficient blood supply affect the fundus of the eye for a longer period of time, there will be thinning of arteries, hemorrhage, edema and exudation on the retina, as well as involvement of the optic nerve and atrophy, which will seriously affect the visual acuity.3. If the blood supply insufficiency affects the anterior segment of the eye, there will be edema and vasodilatation of the conjunctiva of the bulbar conjunctiva, leading to corneal edema, erosion, iridocyclitis, and focal necrosis, which will result in formation of neovascularization of the surface of the iris, or even secondary glaucoma, with swelling and pain in the eye and loss of vision.