Jerky Eye Movement (Nystagmus)
Nystagmus is a condition in which there is involuntary to-and-fro jerky movement of the eye. It is usually seen in both the eyes, and may be a horizontal, vertical or even a twisting (torsional) movement.
Nystagmus occurs because of a congenital condition, and may be due to eye conditions, in which the child may be born with a misformed eye, or due to a block in the transmission of light to the back of the eye.
Nystagmus in adults is usually due to disease of the brain or the inner ear.
Treatment is usually not very effective unless the cause is treated. In children, in certain cases, surgery by which the gaze is rotated to a neutral position works to control the intensity of the nystagmus.
Photophobia (Painful Intolerance to Light)
Typically the eyes screw up in the presence of light, and any attempt to open them is painful, accompanied by profuse tears from the eyes.
The common reasons for photophobia are:
(2) Keratitis (inflammation of a layer of the cornea, the transparent cap on the eye). A small foreign body on the cornea or even a slight scrape or abrasion can cause intense photophobia.
(3) Uveitis or inflammation inside the eye, of the iris diaphragm and its extension, the vascular choroid.
(4) Excessive sensitivity to light, as in albinoes or those with total colour blindness.
(5) Secondary to taking certain drugs, like isoniazid (an anti-TB drug).
(6) Allergic follicles especially in children and young adults.
In essence, all causes of photophobia indicate that something is wrong, somewhere. A visit to an eye doctor is called for.