How Epilepsy Can Affect Your Eyesight
Epilepsy is a neurological condition caused by abnormal electrical signals from damaged brain cells that result in symptoms such as recurring seizures. Since it is a neurological condition, and the eyes and brain are tightly connected, it can have a pronounced effect on the eyes, and it is common for patients to experience vision changes immediately before and during a seizure. This is because epilepsy affects different lobes of the brain, which means how it affects eyes depends on where the seizure occurs in the brain. As a result, symptoms vary from person to person.
What Happens to the Brain During an Epileptic Seizure?
Epilepsy disrupts the ability of your cells to send to and receive messages from the brain. Instead, the brain experiences bursts of electrical energy akin to lightning flashes, which causes all kinds of havoc on the body. Loss of consciousness, loss of mobility, visual disturbances – these are all possible hallmarks of an epileptic seizure.
There are two categories of seizures, each of which are based on where they start in your brain, how your muscles react (or don’t react), and whether you retain awareness during the seizure.
They are:
- Focal onset seizures – these start in only one area of the brain
- Generalized onset seizures - as the name implies, these affect a more widespread network of cells throughout your brain
Effects on the Eyes from Epilepsy
Since epilepsy affects the eyes by disrupting the body’s ability to send and receive messages to the brain, it’s not surprising that this also affects the eyes’ ability to function properly. However, because not all epileptic seizures are the same, different types will cause a person to react in a variety of ways. The variety of symptoms a patient can experience include:
- Uncontrollable jerking of the eyes
- Uncontrollable eyelid flutter
- Staring into space and unable to process visual stimuli
- Loss of field or depth of vision
- Eye deviation
- Auras
- Photosensitivity
- Perceptive illusions (the Alice In Wonderland syndrome)
Visual Disturbances
If a seizure affects the occipital lobe, it may present through symptoms such as uncontrollable jerking of eyelids, rapid eye flickering, and forced closure of the eyelids. Hallucinations such as seeing lights, colors, and even objects that aren’t present are also common.
Auras
An aura is actually a focal aware seizure (FAS) and it often precedes other types of seizures. Auras are thus often perceived as a warning sign that another seizure is on the way. While people often think of auras as solely visual disturbances (such as colored lights or hallucinations), auras are more comprehensive than that, affecting our perceptions of how we hear, see, smell, taste, and feel. Examples of auras include the following:
- An unusual smell or taste
- Sudden intense feelings of fear or joy
- A strange sensation like a "wave" going through the head
- A stiffness or twitching (such as an arm or hand)
- Numbness or tingling
Perceptive Illusions
These are akin to out-of-body experiences, where the patient feels like they are outside of their body and seeing themself from the third person. They include macropsia, micropsia, and depersonalization, and, more rarely, Alice in Wonderland syndrome, whereby the patient perceives a stationary object moving towards or away from them. Palinopsia may also occur, where the patient continues to "see" an image long after it has been removed from their field of vision, as though it is a lingering ghost.
Versive Movements
Versive movements are when the eyes (and/or other parts of the body) are forced involuntarily into unnatural positions.
Photosensitivity
This often occurs just before the onset of a seizure and presents as a sensation of bright, blinding light, or a negative reaction to such a light. However, be careful to not confuse photosensitivity with photosensitive epilepsy. Photosensitivity is what it sounds like – extreme sensitivity to light. Photosensitive epilepsy, however, is a form of epilepsy whereby seizures are triggered by specific light stimuli. Read more for additional information on photosensitive epilepsy.
Treatment
First things first: it should be noted that a person experiencing seizures does not necessarily have epilepsy. Seizures can occur for a variety of reasons, epilepsy being one of them. However, the main marker of epilepsy IS the presence of ongoing seizures. So, if you have epilepsy, you will have seizures.
On another note, studying how a seizure affects the eyes can help doctors assess whether the seizure is epileptic or non-epileptic. The eyes are not just windows to the soul – they are indicators of our overall health as well.
As for treatment, there are many ways to treat epilepsy, including anti-seizure medications, special diets, medical devices and epilepsy surgeries and devices to stop the seizures. At times, something as simple as eyeglasses with specifically tinted lens, such as our functional filters, can be surprisingly effective in not only mitigating the effects of an epileptic seizure, but even helping to prevent them from occurring in the first place.