30/07/2025
Interesting article to understand the mechanism of vision better.
HOW THE EYE AND BRAIN WORK TOGETHER TO HELP US SEE.
There is a direct and vital connection between the eyes and the brain that allows us to see. The eye cannot function in isolation—it relies on the brain to interpret visual information. Likewise, the brain depends on the eye to supply the images it processes.
The Visual Pathway
When light enters the eye, it passes through the lens and lands on the retina, a light-sensitive nerve layer located at the back of the eye.
The retina converts light into electrical impulses. These impulses travel through the optic nerve—a bundle of nerve fibers formed at the optic disc where all retinal nerve cells gather—toward the brain.
Once these signals reach the visual cortex in the brain, they are interpreted into the images we see.
The Role of Blood Flow
The nerve cells in both the eye and the brain require a constant supply of oxygen and nutrients, delivered through the bloodstream. If a blood vessel supplying these areas becomes blocked—such as by a blood clot or fat embolism—the affected structure may become starved of oxygen. This can damage parts of the retina or brain involved in vision, potentially resulting in vision loss.
In particular, damage to retinal cells responsible for central vision or to nerves connected to eye muscles can significantly impair eyesight.
Warning Signs of Oxygen Deprivation
When blood flow to the eye or brain is compromised, it may lead to a stroke-like event. Common warning signs include:
Sudden blurred vision or vision loss
Slurred speech
Facial or limb weakness/paralysis
Dizziness
Bleeding in the eye
These symptoms require urgent medical attention.
Prevention Is Key
Preventative care can reduce your risk of vision-threatening events. It’s recommended that you:
See your general practitioner annually for a full physical exam.
Monitor blood pressure, cholesterol, and blood sugar levels.
Follow up on any unusual symptoms immediately.
If you experience sudden changes in vision, contact Visiomed at 011 476 3119 if you are in the Johannesburg area, or go directly to the nearest emergency room.
Disclaimer:
The author of this article has a medical background but is not a qualified optometrist. This information is intended as a general guideline only. Always consult a qualified healthcare provider for diagnosis or treatment of any eye condition.
