Learn About Common Neuro‑Ophthalmic Conditions

If you’re experiencing changes in your vision or symptoms that may involve the eyes and brain, this page can help you learn more. Below, you’ll find a list of common neuro‑ophthalmic conditions. Click on any condition to open a short overview, watch an explanatory video, and access patient brochures available in multiple languages. These resources are designed to give you clear, trusted information and help you understand what your symptoms may mean as you prepare for your visit with a specialist.

Anisocoria


What is Anisocoria?

Anisocoria is a medical term for unequal pupil size. Normally our pupils are relatively the same size. While small differences in pupil size are normal and can even come and go (physiologic anisocoria), constant and significant differences in pupil sizes may be a sign of damage to the brain or the nerves that control the pupils.

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Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Droopy Eyelids (Ptosis)


What is a Droopy Eyelid (ptosis)? 

Eyelid ptosis is the medical term used to describe a droopy upper eyelid. Eyelid ptosis occurs naturally as we age, but some medical emergencies and diseases can cause eyelid ptosis too. Eyelid ptosis can affect one or both eyes. Sudden onset of eyelid ptosis is a medical emergency.


Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Double Vision


What is Double Vision? 

Double vision, also known as diplopia, occurs when a single object is seen as two images at the same time.  Double vision has many causes and is a frequent reason for patients to see an eye doctor or a specialist such as a neurologist or neuro-ophthalmologist. 

The most important observation to make when having double vision is whether it goes away with covering either eye.  If the double vision is present in one eye by itself, this is monocular double vision.  Alternatively, if the double vision resolves completely with closure of either eye, and is only present with both eyes open, this is binocular double vision.

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Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Giant Cell Arteritis


What is Giant Cell Arteritis?

Giant cell arteritis is an inflammatory condition that can cause vision loss and , less commonly, double vision. GCA is caused by inflammation of blood vessels, primarily in the head and neck.  Sometimes called “temporal arteritis,” GCA frequently affects blood vessels in the temples, causing headaches. GCA can affect other blood vessels in the body, and in severe cases, cause heart attack or stroke.

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Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Homonymous Hemianopia


What is a Homonymous Hemianopia?

Homonymous hemianopia refers to an absence of vision on one side of the visual world in each eye.  The vision loss is on the same side in each eye (for example, the right half of each eye).  The damage that causes this problem is in the brain and not in the eyes.

YouTube Video: Click Here

Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Idiopathic Intracranial Hypertension

What is Idiopathic Intracranial Hypertension/Pseudotumor Cerebri?

Idiopathic intracranial hypertension (IIH), also called pseudotumor cerebri, is a condition in which there is high pressure in the fluid surrounding your brain, spinal cord and optic nerves. This can cause headaches and problems with vision. Although the cause(s) of the condition is not fully understood (the definition of “idiopathic”), we know much about the condition itself.

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Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Leber's Hereditary Optic Neuropathy

What is Leber Hereditary Optic Neuropathy (LHON)?

Leber hereditary optic neuropathy (LHON) is a genetic disease that almost exclusively affects the optic nerves, leading to vision loss (with both eyes eventually affected). In LHON, one of the genes that controls energy production in the optic nerves is abnormal, and over time the waste products of that energy production begin to damage the optic nerves. The abnormal gene is found in the DNA that exists in our mitochondria, the parts of our cells that control energy production, not in the DNA that makes up our chromosomes in the nucleus.

Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Microvascular Cranial Nerve Palsy

What is a Microvascular Cranial Nerve Palsy?

A nerve palsy is an impairment in the function of a nerve, which results in a decrease in function of the corresponding muscles controlled by that nerve.

In microvascular cranial nerve palsy, something affects the blood supply to one of the cranial nerves, causing it not to work. This is usually the result of blockage of the small blood vessels surrounding each nerve, often related to having high blood pressure, diabetes, or high cholesterol.

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Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Migraine Visual Aura

What is a Migraine Visual Aura? 

Migraine visual aura is the most common type of temporary neurological symptom and usually occurs just before or with the onset of a headache. It typically lasts about 30 minutes, but can range between 5 and 60 minutes. Migraines affect about 12% of people and among those with migraines, visual aura occurs in 25-30%. The frequency of the episodes may vary from person to person. The migraine visual aura can even occur without associated headache, which is more common over age 50.

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Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Myasthenia Gravis

What is Myasthenia Gravis?

Myasthenia gravis (MG) is an autoimmune disease in which the body's immune system creates antibodies (proteins that normally protect us) that may attack receptors on your muscles. This results in muscle weakness because the muscles do not receive the signals to contract (tighten). Muscles anywhere within the body may be affected.

In ocular MG, eyelid droop (ptosis) and double vision may occur if the muscles that control the eyelids and eye movements are affected. In generalized MG, muscles of the eyes, limbs, neck, as well as muscles of speaking, swallowing or breathing may also be involved.  Patients with ocular MG can develop generalized MG over time so it is important to monitor closely.

YouTube Video: Click Here

Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Non-Artheritic Anterior Ischemic Optic Neuropathy

What is Non-Arteritic Anterior Ischemic Optic Neuropathy?

Non-arteritic anterior ischemic optic neuropathy (NAION or NA-AION) is a condition that is caused by reduced blood flow to the front part of the optic nerve called the optic disc.  It causes vision loss that is associated with swelling of the optic disc. NAION usually affects one eye at a time, although in rare cases both eyes can be simultaneously affected.  This condition mostly affects older adults and it is the second most common type of optic neuropathy after glaucoma.

YouTube Video: Click Here

Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Optic Disc Drusen

What are Optic Disc Drusen?

Optic disc drusen (ODD) are abnormal deposits of benign, usually calcified material within the optic disc (the front part of the optic nerve that is seen inside in the back of the eye, surrounded by the retina).  We do not know the exact cause of optic disc drusen. They are present in 0.3-2% of people as an isolated case or they may run in some families (inherited). In children, they often are deep in the optic disc and hard to see (buried). Over time, they become more apparent as they enlarge and move closer to the surface of the optic nerve.

YouTube Video: Click Here

Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Optic Neuritis

What is Optic Neuritis?

Optic neuritis is inflammation of the optic nerve. In optic neuritis, the covering around the fibers of the optic nerve (myelin) is damaged by inflammation (demyelination), which typically results in blurred or dark vision.

YouTube Video: Click Here

Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Pituitary Tumor

What is a Pituitary Tumor?

The pituitary gland is a pea-sized gland that sits underneath the base of the brain. It produces and releases many hormones. These hormones control your metabolism, stress level, growth, ovulation and menstruation in women, sperm and testosterone production in men, milk production, and urine production. Because of its many functions, it is often referred to as the “master gland.”

YouTube Video: Click Here

Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Thyroid Eye Disease

What is Thyroid Eye Disease?

Thyroid eye disease (TED) is an autoimmune condition in which your body's immune system triggers inflammation in the eye socket (also called the orbit), affecting the muscles that move the eye and the fatty tissue behind the eye. The disease can cause the eyes to bulge forward (proptosis), the eyelids to open more so it looks like you are staring (eyelid retraction), double vision, decreased vision, red eyelids and eye irritation. Rarely, it can cause pressure on the optic nerve (the nerve that connects the eye to the brain) causing vision loss, or an ulcer of the cornea, the clear front part of the eye, from exposure, causing pain.

YouTube Video: Click Here

Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

Transient Vision Loss

What is Transient Visual Loss? 

Transient visual loss is the term used to describe loss of part or all of the vision in one or both eyes temporarily. Some people do not experience a complete loss of the affected vision and instead describe the abnormality as “blurring” or like “looking through a veil.” The vision typically returns to normal before a person is able to be examined by an ophthalmologist, so the   examination may be normal. Undergoing an eye examination is still very important, as diagnostic clues can sometimes help an eye doctor narrow down the possible causes. Even if the vision returns to normal, transient visual loss can be a sign of serious abnormalities of the eye, brain, or blood vessels that can lead to permanent vision loss or even to a brain stroke, without prompt recognition and treatment.

YouTube Video: Click Here

Patient Brochure: Download Here

Patient Brochures in Other Languages:

Patient brochures in Hindi and Portuguese are available upon request. Please email NANOS Executive Office at info@nanosweb.org and they'll be happy to assist you. 

These patient brochures are a copyright of NANOS.  NANOS reserves all rights. These brochures are produced and made available for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.

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