Symptoms of partial or total blindness can vary in adults, children, and infants. Regular eye examinations can help diagnose certain eye conditions, including glaucoma, that may lead to blindness early.

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 highly compromised vision. 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 vision. Have someone bring you to the emergency room for treatment. Don’t wait for your vision to return.

There are no cures for blindness, but there are ways to help you manage complete or partial blindness.

Adults and infants experience different symptoms of blindness. Here’s what to look for:

Symptoms of blindness in adults

If you’re partially blind, you might have the following symptoms:

  • cloudy vision
  • an inability to see shapes
  • seeing only shadows
  • difficulty seeing at night
  • tunnel vision

Symptoms of blindness in infants

Children’s visual systems begin to develop in the womb, but they don’t fully form until about 2 years of age, according to the American Optometric Association.

By 3 months 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
  • difficulty focusing their eyes
  • chronic eye redness
  • chronic tearing from their eyes
  • a white instead of black pupil
  • trouble following an object with their eyes
  • abnormal eye alignment or movement after 6 months of age

The following eye 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 detail and typically affects older adults
  • Cataracts: more common in older adults and can cause cloudy vision
  • Amblyopia: can make it difficult to see details and may lead to vision loss; also known as lazy eye
  • Optic neuritis: optic nerve inflammation that can cause temporary or permanent vision loss
  • Retinitis pigmentosa: retina damage that leads to blindness only in rare cases
  • Tumors: growths that can affect the retina or optic nerve and cause blindness

Blindness is a potential complication if you have diabetes or have a stroke. Other common causes of blindness include:

  • issues during fetal development
  • eye injuries
  • complications from eye surgery

Causes of blindness in infants

The following conditions can cause blindness in infants:

  • cataracts
  • amblyopia (lazy eye)
  • strabismus (crossed eyes) if there is also amblyopia
  • ptosis (droopy eyelid) if there is also amblyopia, though this is rare
  • glaucoma at birth
  • retinopathy of prematurity (ROP), which occurs in premature babies when the blood vessels that supply their retina aren’t fully developed

The following can increase the risk of blindness:

Diagnosing blindness in adults and infants involves testing from eye doctors.

Diagnosing blindness in adults

A thorough eye exam by an eye doctor called an optometrist helps determine the cause of your blindness.

The 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 will examine the general health of your eyes using a slit lamp. It’s a low power microscope paired with a high intensity light.

They may also dilate your eyes if they need to see the back of your eyes, such as the optic nerves and retina.

Diagnosing blindness in infants

A pediatrician will screen your baby for eye problems shortly after birth. When your baby is 6 months old, have an eye doctor or pediatrician check them again for visual acuity, focus, and eye alignment.

A pediatric ophthalmologist typically performs the first screening within 4 to 6 weeks after birth if your baby is born before 31 weeks of gestation or weighs less than 1,500 grams (3.3 pounds).

The doctor will examine your baby’s eye structures and determine whether they can follow a light or colorful object with their eyes.

Your child should be able to pay more attention to visual stimuli more easily by 8 weeks old. After 8 weeks, their vision continues to improve.

If your child doesn’t focus on colorful objects by 5 months old, have their eyes examined right away.

If you experience partial blindness that can’t be corrected, an eye doctor can provide guidance on how to function well 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.

Surgery or medications may also help treat partial blindness, but there’s no current way to cure complete blindness.

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 adaptive products, such as a specialized smartphone, color identifier, and accessible cookware. Adaptive sporting equipment, like sensory soccer balls, is also available.

Treatment that is preventive and sought immediately improves a person’s long-term outlook for restoring impaired vision and slowing blindness.

Surgery can effectively treat cataracts, but cataracts don’t necessarily result in blindness.

Early diagnosis and treatment are also important in cases of glaucoma and macular degeneration to help slow or stop blindness.

Schedule regular eye examinations to detect eye diseases that may result in blindness. If you have certain eye conditions, such as glaucoma, treatment with medication can help prevent blindness.

To help prevent blindness, the American Optometric Association recommends getting your child’s eyes examined:

  • at 6 months old
  • at 3 years old
  • every year between 6 and 17 years old

If you notice symptoms of blindness between routine visits, make an appointment with an eye doctor immediately.

Adults, children, and infants may experience different symptoms of partial and total blindness. It’s important to schedule regular eye examinations to help prevent blindness or detect early diagnoses of certain eye conditions that may result in partial or complete blindness.

Talk with an eye doctor right away if you or your child are experiencing symptoms of total or partial blindness.