Title: Vision Loss, Sudden - Eye Disorders - Merck Manuals Consumer Version
Headings: Vision Loss, Sudden
Vision Loss, Sudden
An Inside Look at the Eye
Causes of Sudden Vision Loss
When the Visual Pathways Are Damaged
Common causes
Less common causes
How and Why Blindness Develops
Table
Evaluation of Sudden Vision Loss
When to see a doctor
What the doctor does
Testing
Treatment of Sudden Vision Loss
Spotlight on Aging: Vision Loss in Older People
Key Points about Sudden Vision Loss
Others also read
Also of Interest
Merck and the Merck Manuals

Content: Blindness can occur under the following circumstances: Light cannot reach the retina. Damage to the cornea caused by infections such as herpes keratoconjunctivitis or an infection that follows contact lens overwearing, which results in an opaque corneal scar
Damage to the cornea caused by vitamin A deficiency (keratomalacia), which causes dry eyes and results in an opaque corneal scar (rare in developed nations)
Damage to the cornea caused by a severe injury that results in an opaque corneal scar
A cataract, which causes loss of clarity of the lens
Light rays do not focus on the retina clearly. Imperfect focusing of light rays on the retina (refraction errors) that cannot be fully corrected with eyeglasses or contact lenses (such as from certain types of cataracts)
The retina cannot sense light rays normally. Detached retina
Diabetes mellitus
Macular degeneration
Retinitis pigmentosa
Inadequate blood supply to the retina, usually due to a blockage of the retinal artery or vein, which may be caused by inflammation of the blood vessel wall (such as that caused by giant cell arteritis), or due to a blood clot that travels to the eye from somewhere else (such as from the carotid artery in the neck)
Infection of the retina (such as from Toxoplasma or fungi)
Nerve impulses from the retina are not transmitted to the brain normally. Disorders affecting the optic nerve or its pathways inside the brain, such as brain tumors, strokes, infections, and multiple sclerosis
Glaucoma
Inflammation of the optic nerve ( optic neuritis)
The brain cannot interpret information sent by the eye. Disorders that affect the areas of the brain that interpret visual impulses (visual cortex), such as strokes and tumors
Table
Some Causes and Features of Sudden Loss of Vision
Cause
Common Features*
Diagnosis †
Sudden loss of vision without eye pain
Sudden, brief loss of vision in one eye resulting from a transient ischemic attack (called amaurosis fugax)
Blindness in one eye lasting minutes to hours
Sometimes MRI or CT
Ultrasonography of the carotid arteries
Echocardiogram (ultrasound of the heart)
ECG
Continuous monitoring of heart rhythm
Blockage of the central retinal artery (the artery that carries blood to the retina)
Almost instantaneous, complete loss of vision in one eye
In people with risk factors for atherosclerosis (such as high blood pressure, abnormal blood lipids, or cigarette smoking)
Measurement of ESR (a blood test), C-reactive protein, and platelets
Sometimes MRI or CT
Ultrasonography of the carotid arteries
Echocardiogram (ultrasound of the heart)
ECG
Continuous monitoring of heart rhythm (Holter monitor)
Blockage of the central retinal vein (the vein that carries blood away from the retina)
In people with risk factors for this disorder (such as diabetes, high blood pressure, a tendency for blood to clot excessively, or sickle cell disease)
A doctor's examination
Vitreous hemorrhage (bleeding into the vitreous humor—the jellylike substance that fills the back of the eyeball)
In people who have had specks, strings, or cobwebs in their field of vision (floaters) or who have risk factors for vitreous hemorrhage (such as diabetes, a tear in the retina, sickle cell disease, or an eye injury)
Usually loss of the entire field of vision (not in just one or more spots)
Examination by an ophthalmologist
Sometimes ultrasonography of the retina
Giant cell (temporal) arteritis (inflammation of the large arteries of the head, neck, and upper body), which can block blood flow to the optic nerve
Sometimes headache, pain while combing the hair, or pain in the jaw or tongue when chewing
Sometimes aches and stiffness in the large muscles of the arms or legs (polymyalgia rheumatica)
Measurement of ESR, C-reactive protein, and platelets
Biopsy of the temporal artery
Ischemic optic neuropathy (damage of the optic nerve caused by blockage of its blood supply)
In people with risk factors for this disorder (such as diabetes or high blood pressure) or in people who have had an episode of very low blood pressure, which sometimes causes fainting
A doctor's examination
Measurement of ESR, C-reactive protein, and platelets
Sometimes biopsy of temporal artery
Sometimes carotid artery Doppler (ultrasound of the neck veins) and echocardiogram (ultrasound of the heart)
Macular hemorrhage (bleeding around the macula—the most sensitive part of the retina) resulting from age-related macular degeneration
Usually in people known to have age-related macular degeneration or in people with risk factors for blood vessel disorders (such as high blood pressure, cigarette smoking, or abnormal blood lipids)
A doctor's examination
Ocular migraine (migraines that affect vision)
Shimmering, irregular spots that drift slowly across the field of vision of one eye for about 10 to 20 minutes
Sometimes blurring of central vision (what a person is looking at directly)
Sometimes a headache after the disturbances in vision
Often in young people or in people known to have migraines
A doctor's examination
Detachment of the retina
Sudden, spontaneous flashes of light that can look like lightning, spots, or stars (photopsias) that occur repeatedly
Loss of vision that affects one area, usually what is seen out