Blindness is the inability to see anything, including light.
If you’re partially blind, you have limited vision. For example, you may have blurry vision or the inability to distinguish the shapes of objects. Complete blindness means you can’t see at all.
Legal blindness refers to vision that’s highly compromised. What a person with regular vision can see from 200 feet away, a legally blind person can see from only 20 feet away.
Seek medical attention right away if you suddenly lose the ability to see. Have someone bring you to the emergency room for treatment. Don’t wait for your vision to return.
Depending on the cause of your blindness, immediate treatment may increase your chances for restoring your vision. Treatment may involve surgery or medication.
If you’re completely blind, you see nothing. If you’re partially blind, you might experience the following symptoms:
- cloudy vision
- an inability to see shapes
- seeing only shadows
- poor night vision
- tunnel vision
Symptoms of blindness in infants
Your child’s visual system begins to develop in the womb. It doesn’t fully form until about 2 years of age.
By 6 to 8 weeks of age, your baby should be able to fix their gaze on an object and follow its movement. By 4 months of age, their eyes should be properly aligned and not turned inward or outward.
The symptoms of visual impairment in young children can include:
- constant eye rubbing
- an extreme sensitivity to light
- poor focusing
- chronic eye redness
- chronic tearing from their eyes
- a white instead of black pupil
- poor visual tracking, or trouble following an object with their eyes
- abnormal eye alignment or movement after 6 months of age
The following eye diseases and conditions can cause blindness:
- Glaucoma refers to different eye conditions that can damage your optic nerve, which carries visual information from your eyes to your brain.
- Macular degeneration destroys the part of your eye that enables you to see details. It usually affects older adults.
- Cataracts cause cloudy vision. They’re more common in older people.
- A lazy eye can make it difficult to see details. It may lead to vision loss.
- Optic neuritis is inflammation that can cause temporary or permanent vision loss.
- Retinitis pigmentosa refers to damage of the retina. It leads to blindness only in rare cases.
- Tumors that affect the retina or optic nerve can also cause blindness.
Blindness is a potential complication if you have diabetes or have a stroke. Other common causes of blindness include:
- birth defects
- eye injuries
- complications from eye surgery
Causes of blindness in infants
The following conditions can impair vision or cause blindness in infants:
- infections, such as pink eye
- blocked tear ducts
- strabismus (crossed eyes)
- amblyopia (lazy eye)
- ptosis (droopy eyelid)
- congenital glaucoma
- retinopathy of prematurity (ROP), which occurs in premature babies when the blood vessels that supply their retina aren’t fully developed
- visual inattention, or delayed development of your child’s visual system
The following categories of people are at risk for blindness:
- people with eye diseases, such as macular degeneration and glaucoma
- people with diabetes
- people who have a stroke
- people undergoing eye surgery
- people who work with or near sharp objects or toxic chemicals
- premature babies
A thorough eye exam by an optometrist will help determine the cause of your blindness or partial loss of vision.
Your eye doctor will administer a series of tests that measure:
- the clarity of your vision
- the function of your eye muscles
- how your pupils react to light
They’ll examine the general health of your eyes using a slit lamp. It’s a low-power microscope paired with a high-intensity light.
Diagnosing blindness in infants
A pediatrician will screen your baby for eye problems shortly after birth. At 6 months of age, have an eye doctor or pediatrician check your child again for visual acuity, focus, and eye alignment.
The doctor will look at your baby’s eye structures and see whether they can follow a light or colorful object with their eyes.
Your child should be able to pay attention to visual stimuli by 6 to 8 weeks of age. If your child doesn’t react to light shining in their eyes or focus on colorful objects by 2 to 3 months of age, have their eyes examined right away.
Have your child’s eyes examined if you notice crossed eyes or any other symptoms of impaired vision.
In some cases of vision impairment, one or more of the following may help restore vision:
- contact lenses
If you experience partial blindness that can’t be corrected, your doctor will provide guidance on how to function with limited vision. For example, you can use a magnifying glass to read, increase the text size on your computer, and use audio clocks and audiobooks.
Complete blindness requires approaching life in a new way and learning new skills. For example, you may need to learn how to:
- read Braille
- use a guide dog
- organize your home so you can easily find things and stay safe
- fold money in distinct ways to distinguish bill amounts
You can also consider getting some adaptive products, like a specialized smartphone, color identifier, and accessible cookware. There’s even adaptive sporting equipment, like sensory soccer balls.
A person’s long-term outlook for restoring vision and slowing vision loss is better when treatment is preventive and sought immediately.
Surgery can effectively treat cataracts. They don’t necessarily result in blindness. Early diagnosis and treatment are also important in cases of glaucoma and macular degeneration to help slow down or stop vision loss.
To detect eye diseases and help prevent vision loss, get regular eye examinations. If you receive a diagnosis of certain eye conditions, such as glaucoma, treatment with medication can help prevent blindness.
To help prevent vision loss, the American Optometric Association recommends you have your child’s eyes examined:
- at 6 months of age
- at 3 years of age
- every year between 6 and 17 years old
If you notice symptoms of vision loss between routine visits, make an appointment with their eye doctor immediately.