This condition usually in found during a routine eye exam or if a patient experiences sudden partial vision loss. A retinoblastoma, however, is a malignant tumor of the retina that occurs in one or both eyes, usually in a child younger than 5. Symptoms may not occur in the child but will show up later as affected vision in part of one eye. We hope your friend has had the necessary investigative tests done and will find some treatment, if not in China, then perhaps here in the United States. Blood flows from the heart through arteries.
Arteries turn into smaller arteries called arterioles.
Blood reaches the ocular tissue through the capillary beds, and then returns to the heart through veins. The eye contains hundreds of millions of specialized nerve cells, specifically rods and cones. Cones are responsible for color vision and detailed vision and function best under bright illumination. The pupillary response to bright light is to constrict to prevent excessive light from entering the eye. Blood flow is reduced when constriction occurs.