How Do People Become Blind & What Causes Blindness: Answers

written by

Have you ever wondered about the various factors that contribute to vision loss and what can cause blindness? Understanding the causes of blindness is crucial for raising awareness and promoting preventive measures. In this article, we’ll delve into the intricacies of

what causes people to go blind, exploring the diverse factors and conditions. From the underlying causes to the preventive strategies, we’ll uncover the answers to questions such as “how can you go blind”.

How Does Blindness Work? Types of Vision Impairment

Types of Vision Impairment
  1. Partial Blindness (Low Vision): Retaining some level of vision.
  2. Complete Blindness: Inability to see or detect light, an exceedingly rare condition.
  3. Congenital Blindness: Vision impairment present from birth, attributed to inherited eye conditions or non-inherited birth defects.
  4. Legal Blindness: Central vision of 20/200 in the best-seeing eye, even with corrective lenses, or severe reduction in the field or peripheral vision.
  5. Nutritional Blindness: Vision loss due to vitamin A deficiency, potentially leading to xerophthalmia and reduced night vision.
  6. Color Blindness (Color Deficiency): Altered perception of colors, often inherited or acquired due to retinal or optic nerve issues; achromatopsia results in seeing only black, white, or shades of gray.
  7. Preventable or Avoidable Blindness: Refers to blindness resulting from treatable conditions, which individuals may not address due to limited access to eye or healthcare, leading to complications like diabetes-related retinopathy or hypertensive retinopathy.

What causes blindness?

How do people go blind? Understanding the myriad factors that contribute to vision loss is crucial. Blindness causes are diverse, ranging from genetic mutations to age-related degeneration. The majority of global blindness cases stem from various eye diseases . Cataracts take the lead among adults aged 50 and above, followed by glaucoma, uncorrected refractive error, age-related macular degeneration (AMD), and diabetic retinopathy, as reported in a February 2021 analysis in the Lancet Global Health.

While these eye conditions are prevalent contributors to blindness, it’s crucial not to assume impending blindness if you have any of these issues. Treatments exist for each condition, although the level of treatability varies.


A cataract refers to a cloudy area that forms in the lens of the eye, which is the transparent part responsible for focusing light. This condition is prevalent as individuals age, with more than half of Americans aged 80 or above either having cataracts or undergoing surgery to address them.

Initially, cataracts may not manifest noticeable symptoms. However, as time progresses, they can cause blurry or hazy vision, diminish color perception, and impede daily activities such as reading.

How do you get blind with cataracts? The prolonged presence of cataracts may eventually result in vision loss. Fortunately, cataract surgery offers a safe and effective solution to eliminate cataracts, correcting associated vision problems and enhancing overall eyesight.

Refractive errors

Refractive errors pose common challenges to clear vision by affecting how light focuses on the retina—a light-sensitive tissue at the back of the eye. With over 150 million Americans affected, refractive errors are prevalent, often undetected, hindering optimal vision. Regular eye exams are crucial for identifying and addressing these issues.

Refractive errors manifest as blurred vision due to the eye’s shape hindering proper light focus on the retina. Myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia are common types, all correctable with appropriate measures.

Unfortunately, the global impact of uncorrected refractive errors contributes significantly to vision impairment and blindness, emphasizing the need for timely intervention. Treatment options include personalized glasses, contact lenses, or refractive laser surgery tailored to the specific refractive error and its progression. Early detection and corrective measures can significantly enhance overall visual health.

Types of Refractive Errors:

Types of Refractive Errors
  1. Nearsightedness (Myopia): Blurring of distant objects.
  2. Farsightedness (Hyperopia): Blurring of nearby objects.
  3. Astigmatism: Blurring or distortion of both distant and nearby objects.
  4. Presbyopia: Difficulty focusing on close objects, common in middle-aged and older adults.

Macular degeneration

Macular degeneration, or age-related macular degeneration (AMD), stands as a prominent cause of vision impairment among Americans aged 50 and older. Over 10 million Americans grapple with AMD, with about 2.2 million facing advanced cases that threaten their vision.

In the “dry” form, characterized by the presence of small deposits called drusen, the macula—the region responsible for central vision and detailed, colorful sight—undergoes desiccation. The more severe “wet” variant witnesses the growth of abnormal blood vessels beneath the macula, leading to fluid leakage or bleeding.

How do you become blind with macular degeneration? While AMD may not induce complete blindness, it can result in the loss of central vision, complicating tasks such as recognizing faces, driving, and other daily activities. Although no cure exists, certain vitamins and minerals, particularly those abundant in leafy green vegetables, may help alleviate its impact. Regular eye exams are crucial for early detection and management of AMD.


Glaucoma stands as a collective term for a group of eye diseases that jeopardize vision and, if left unchecked, can lead to blindness. The primary culprit is the impairment of the optic nerve, situated at the back of the eye.

The progression of symptoms in glaucoma can be subtle, often escaping immediate notice. The most effective means of diagnosis is a comprehensive dilated eye exam, revealing any underlying glaucomatous conditions.

While a definitive cure for glaucoma remains elusive, early intervention can frequently halt further damage and safeguard your eyesight. In the United States, open-angle glaucoma emerges as the most prevalent type, though less common variants like angle-closure glaucoma and congenital glaucoma also exist.

How can you get blind with glaucoma? Glaucoma typically manifests without apparent symptoms in its initial stages, with around half of those affected being unaware of their condition. As the disease advances, gradual vision loss, starting from the peripheral vision, becomes noticeable. The imperceptible nature of these changes often delays recognition, emphasizing the importance of regular eye examinations. Without timely intervention, glaucoma can progress to irreversible blindness.

Demystifying Diabetic Retinopathy

Diabetic retinopathy (DR) emerges as a prevalent complication of diabetes, standing as the foremost cause of blindness among American adults. It unfolds through distinct stages, reflecting progressive damage to the retinal blood vessels, crucial for maintaining optimal vision:

Demystifying Diabetic Retinopathy
  1. Mild Nonproliferative Retinopathy: Characterized by microaneurysms.
  2. Moderate Nonproliferative Retinopathy: Involves blockage in some retinal vessels.
  3. Severe Nonproliferative Retinopathy: Exhibits increased vessel blockage, leading to a deprived retina.
  4. Proliferative Retinopathy: The most advanced stage, marked by the growth of new blood vessels.

Diabetic retinopathy typically impacts both eyes, necessitating vigilant management to mitigate risks. Effective disease control involves maintaining optimal blood sugar, blood pressure, and lipid levels. Early detection and prompt treatment significantly reduce the risk of vision loss. Unfortunately, a substantial portion of patients faces delayed diagnoses or lacks regular eye examinations, contributing to its status as a leading cause of blindness among U.S. working-aged adults aged 20–74 years.

Diabetic retinopathy is alarmingly common, affecting over 2 in 5 individuals with diabetes, particularly posing heightened risks for older Hispanic populations. This condition arises when elevated blood sugars obstruct retinal vessels, progressing through various stages and posing a potential threat to vision. Treatment options encompass injections, laser treatments, and surgery, with optimal blood sugar control serving as a key preventive measure against its risks.

Other cases

other cases of blindness

Total blindness, marked by an absence of light perception, often results from severe conditions such as:

  1. Severe Trauma or Injury
  2. Complete Retinal Detachment
  3. End-Stage Glaucoma
  4. End-Stage Diabetic Retinopathy
  5. Severe Internal Eye Infection (Endophthalmitis)
  6. Vascular Occlusion (Stroke in the Eye)


The treatment for visual impairment or blindness varies based on the underlying cause.

  • In regions with prevalent refractive errors causing poor vision, providing and prescribing glasses can often address the issue.
  • Nutritional causes of blindness may be mitigated through dietary adjustments.
  • Cataract-related blindness, affecting millions globally, can often be resolved through cataract surgery.
  • Inflammatory and infectious causes of blindness may find relief through medication, whether in the form of drops or pills.
  • Corneal transplantation is a potential solution for individuals experiencing vision loss due to corneal scarring.
human eye

How can I decrease chances of going blind?

While you can’t prevent all types of blindness, there are steps you can take to minimize the risk of avoidable vision loss. Governments and communities are working to combat diseases that lead to blindness, making medications more accessible globally.

On a personal level, consider these actions to reduce the risk of partial or total blindness:

  • Schedule regular eye check-ups and follow healthcare providers’ advice. Promptly address any changes in vision or eye problems and use prescription glasses or contact lenses as prescribed.
  • Manage diabetes and control high blood pressure to maintain stable health.
  • Wear protective gear, including sunglasses, during work, motorcycle riding, or contact sports.
  • Include regular exercise in your routine, tailored to your health condition.
  • Be informed about your family’s health history.
  • Quit smoking or avoid starting.
  • Prevent eye infections by consistently washing your hands before handling contacts and adhering to instructions on changing them.

In conclusion, the journey into understanding how people get blind unveils a spectrum of causes and conditions that affect vision. From genetic factors to preventable diseases, the complexities surrounding blindness underscore the importance of proactive measures. Regular eye exams, healthy lifestyle choices, and disease management play pivotal roles in mitigating the risk of vision loss. 

When does vision decline typically begin?

Starting in the early to mid-40s, many adults may encounter difficulties with clear near vision, particularly when engaged in activities like reading and computer work. This issue is commonly experienced by adults aged 41 to 60.

Is living with blindness challenging?

Even individuals with vision impairments, including those worse than legally blind, may retain some perception of light, colors, or objects in their peripheral or central visual fields. While navigating with limited sight can be perplexing and demanding, complete blindness presents even greater challenges, especially initially.

Can someone be completely blind?

Total blindness refers to individuals with a complete absence of light perception, often documented as no light perception (NLP). Merely 15% of people with eye disorders experience total blindness, as the majority of those with visual impairments retain some level of vision.