Timing and kinematics. Saccades are one of the fastest movements produced by the human body (blinks may reach even higher peak velocities). The peak angular speed of the eye during a saccade reaches up to 900°/s in humans; in some monkeys, peak speed can reach 1000°/s.

1. Roll up a piece of paper in the shape of a tube.
2. Hold the tube up in front of one eye. Keep both eyes open and look forward.
3. Take your free hand (the one not holding the tube), and hold it up in front of the eye that is not looking through the tube. Keep this hand open with your palm facing your face.

The trick is to look left or right without uncrossing. Say you were looking at someone else, face to face. You cross your eyes splitting them into two images. You can then look at the far left ear, or the far right ear, and only one of your eyes will move.

Practice crossing your eyes by looking at the tip of your nose with both eyes. Slowly slide your gaze upwards to the bridge of your nose while looking inward. At this distance, your eyes should cross. These techniques may use muscles that don’t usually get much exercise, which can cause fatigue.

While the human eye muscles do function independently, there is a central brain circuit that controls eye movements. As a result, there is only one visual focal point for the whole brain, and both eyes track to it. That is why you can’t move the eyes independently.

Problem statement: it’s easy to move your eyes smoothly when you are tracking a moving object. This is called smooth pursuit. However, triggering smooth pursuit without a moving object is notoriously hard.

Nystagmus is a condition that causes involuntary, rapid movement of one or both eyes. It often occurs with vision problems, including blurriness.

Saccades are rapid, ballistic movements of the eyes that abruptly change the point of fixation. They range in amplitude from the small movements made while reading, for example, to the much larger movements made while gazing around a room. The time course of a saccadic eye movement is shown in Figure 20.4.

Saccadic deficiencies can be treated using vision therapy at any age, and it can help to improve reading speed and ability. Some of the treatments that might be used are monocular exercises done with a patch including charts, games, hitting a Marsden Ball, and doing eye stretches and jumps.

Saccades were of normal velocity but hypermetric in all directions, particularly on re-centering. There was prominent saccadic oscillation in the horizontal plane on central refixation, particularly from leftward gaze (Figure 1). Saccadic pulsion was evident during both horizontal and vertical saccades.

The frontal eye field can thus control eye movements by activating selected populations of superior colliculus neurons. These results suggest that the frontal eye fields and the superior colliculus provide complementary pathways for the control of saccades.

occipital lobe

Cranial nerves III (CNIII) (oculomotor), IV (trochlear), and VI (abducens) control the position of the eyeballs; CNIII influences the position of the eyelids and the size of the pupils.

Nystagmus is most commonly caused by a neurological problem that is present at birth or develops in early childhood. Acquired nystagmus, which occurs later in life, can be the symptom of another condition or disease, such as stroke, multiple sclerosis or trauma.

Dancing Eye Syndrome (DES; also known as Ospoclonus Myoclonus Syndrome, OMS) is a rare condition characterised by unusual eye movements, which are almost always present, along with unsteadiness, jerky movements of the trunk and limbs, irritability and sleep disturbance.

In most cases, acquired nystagmus goes away after the cause has been treated. In rare cases, it can be caused by a serious medical condition such as a stroke, cataracts, an inner ear disorder, or a head injury.

Acquired nystagmus may be caused by diseases of the eye or inner ear, multiple sclerosis, stroke, anti-seizure medication such as phenytoin [2], alcohol intoxication, deficiency of B12 or thiamine, and brain tumors. Moreover, nystagmus can be caused by seizure activity, that is, a type of epilepsy.

There are cases where nystagmus resolves on its own. This is typically when someone has acquired nystagmus due to a medical condition. Treating the underlying condition could resolve the nystagmus. While there is no cure for this condition, treatments methods can be beneficial for many people.

According to Demian Brown, a Toronto-based psychotherapist and registered clinical social worker, twitching of your face and body is a common symptom of anxiety — especially around the eyes. “The twitches around the eyes, they’re called blepharospasm,” Brown told Global News.

Symptoms of simple partial seizures are:

• Muscle tightening.
• Unusual head movements.
• Blank stares.
• Eyes moving from side to side.
• Numbness.
• Tingling.
• Skin crawling (like ants crawling on the skin)
• Hallucinations- seeing, smelling, or hearing things that are not there.

Absence seizures involve brief, sudden lapses of consciousness. They’re more common in children than in adults. Someone having an absence seizure may look like he or she is staring blankly into space for a few seconds. Then, there is a quick return to a normal level of alertness.

A simple partial seizure may involve sensory, motor, psychic, or autonomic symptoms. These symptoms result in the person experiencing an unusual sensation, feeling or movement called an aura. The aura may be a distortion in sight, sound, or smell where a person sees, hears, smells things that are not there.

Causes of simple partial seizures include traumatic brain injury, which can cause a scar on the brain that can disturb normal brain electrical signals and trigger seizures. Also, brain irritation from surgery, stroke, or tumor can interfere with brain electrical activity and cause simple partial seizures.

Some warning signs of possible seizures may include: Odd feelings, often indescribable. Unusual smells, tastes, or feelings. Unusual experiences – “out-of-body” sensations; feeling detached; body looks or feels different; situations or people look unexpectedly familiar or strange.

Migralepsy (migraine-triggered seizures) is the term used when a seizure occurs during or within 1 hour of a typical migraine aura attack. Reversible brain MRI abnormalities have been reported in a patient with migraine-triggered seizure, possibly as a consequence of supratentorial focal cerebral edema.