What is the Retina?

What is the Retina?

The retina is located in the inner-most part of the eye.  It contains the light sensitive part of your eyes, and the nerve tissue and cellular networks needed for vision. The retina contains two types of cells that absorb the light needed for vision: Rods and Cones.  The rods enable us to see in dim light and allow for black and white vision.  The cones enable us to see in well-lit areas and are responsible not only for color vision, but for high-definition vision as when reading small print or working on a computer.

The retina also contains ganglion cells, that among other things, contribute to the circadian rhythms (or sleep/wake cycle) of your body.

When light enters the eye and then gets absorbed by the retina, it is converted into electrical signals.  These electrical signals are then transmitted to your brain through the optic nerve.  The optic nerve takes these electrical signals to the visual cortex (located at the back of our brains). It is in the visual cortex that those electrical signals are converted into and interpreted as sight.

The human retina is extremely complex.  It’s made of 10 different layers, and each layer is either directly or indirectly responsible for vision.  The retina also houses a number of blood vessels, as all the nerves need a constant supply of oxygen and nutrients found in blood.  If there is a problem with the flow of blood to the retina, it can mean major problems for your vision.  These vision problems can range from blurry vision to complete blindness. Common conditions that affect blood flow to your eyes are High Blood Pressure, Diabetes, and High Cholesterol (Atherosclerosis), among others.


Retinal Conditions

The blood supply is just one part of the retina that can cause major problems with vision.  A list of common problems that ophthalmologists and retina specialists treat would contain the following:

Vitreous Detachment: Vitreous detachment occurs when the vitreous (a gel-like substance in your eyes that contains many protein fibers) becomes separated from the retina.  You may or may not experience symptoms, but the most common symptom patients may experience is floaters in your vision.

Flashes and Floaters: Flashes and floaters can be a sign of a retinal tear or retinal detachment.  If you are experiencing these symptoms, one should see an eye care specialist urgently.

Retinal Tear/Retinal Detachment: Retinal tears or retinal detachments can happen when the retina is torn or separated from the underlying support tissue.  These are serious conditions that can threaten your vision, and one should see an eye care specialist urgently.

Diabetic Retinopathy: Diabetic Retinopathy is a condition that is a complication of diabetes that can damage the retina.  The patient may not notice any symptoms in the beginning, but symptoms can appear later. Diabetes can cause bleeding, swelling and/or scarring in the retina. This condition can lead to blindness if left untreated. It can cause many symptoms, but the most common are blurry vision, reddening of vision, vision loss, eye pain, etc.

Macular Degeneration: Macular Degeneration results from deterioration of the light receptors (rods and cones) in the innermost layer of the retina.  Symptoms can include blurred or distorted vision, and central vision loss. Macular Degeneration has a genetic component and can run in families. If left untreated, this condition can cause blindness.

Age Related Macular Degeneration: This refers to macular degeneration that is experienced as a patient ages, it can be different from the familial type.

Epiretinal Membrane: This condition happens when a layer of scar tissue forms on the retina, usually after a vitreous detachment. The symptoms of epiretinal membrane are usually blurry vision or distorted vision but can sometimes cause vision loss from macular holes.

Macular Holes: This condition can be caused by anything that pulls on the macular tissue, such as an epiretinal membrane, vitreous detachment, diabetic scarring, etc. This condition can be vision threatening, and one should see an eye care specialist urgently.

Retinitis Pigmentosa: Retinitis Pigmentosa is a genetic disease that causes damage to the retina, making your vision worsen over time and can lead to loss of peripheral (side) vision loss and eventually central vision loss and blindness.

CRVO / BRVO (Retinal Stroke): This refers to an occlusion (blockage) of the retinal vein. This occlusion causes a stroke of the retina. Symptoms can include central or peripheral (side) vision loss and can sometimes be sudden. These are serious conditions that can threaten one’s vision, and one should see an eye care specialist urgently.

CRAO / BRAO (Retinal Stroke): These conditions often begin with a sudden loss of vision resulting from a blockage of an artery in the optic nerve.  Central or peripheral (side) vision loss may occur, as well as a blurry spot in your field of vision. These are serious conditions that can threaten your vision, and you should see an eye care specialist immediately.

Cystic/Retina Edema (Swollen Macula): This is a condition where fluid accumulates in the retina. It is normally painless, but can cause blurry or distorted vision. The underlying condition needs to be treated or it can continue to occur and can even worsen over time. These are serious conditions that can threaten one’s vision, and one should see an eye care specialist urgently.

In addition to this list, there are many conditions related to the retina that cause patients to see a retina specialist.  Some of these conditions can threaten your vision and require immediate attention.


At Vision Specialists of California, it is our duty to fully evaluate and treat your eyes according to the guidelines set forth by the American Academy of Ophthalmology. We treat you with the time and respect you deserve as not just another patient, but as a valued member of our community. Please Call (619) 501-9050 today to set up a consultation with a specialist in our office.


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