See the global blindness burden by cause and continent.

Age-related macular degeneration is the primary cause of blindness in older Americans.

World health experts expect more than 240 million global cases of AMD in 2030

The World Health Organization estimated in 2019 that by 2020 there would be roughly 195.6 million cases of age-related macular degeneration and projected that the number would continue to grow. (Some users may experience a paywall.)

See how cataracts—a leading cause of vision loss globally—form and how sound waves are often used to help remove them.

See the geographic spread and incidence of malaria

This graphic shows the estimated global burden of malaria in 2025 as new cases per 1000 people at risk.

US macular degeneration burden is based on statistical modeling and Medicare claims

Prevalence estimates for age-related macular degeneration in the US are usually based on the Vision and Eye Health Surveillance System. Disease numbers are generated using Bayesian meta-regression (a type of statistical modeling), which pulls together information from multiple sources, including Medicare claims.

See worldwide hearing loss by age group and country

This 2023 data from the Institute for Health Metrics and Evaluation shows the estimated number of people with complete hearing loss in different age groups per 100,000 people in the population. Individuals aged 70 or older make up the largest group with this type of hearing deficit.

See what regions report new leprosy cases

This graphic shows the burden of leprosy by region for 2023, based on data provided from the World Health Organization, which collates this information. Southeast Asia leads in the number of cases by region. (Some readers may experience a paywall.)

There may be 500,000 additional malaria deaths by 2050 according to peer-reviewed research published in 2026.

See how anxiety disorder rates vary across 200+ countries, with Portugal, Malta, Brazil, and Iran reporting the highest burdens.

Trauma-related amputations are primarily from falls, then car accidents and related traumas, followed by mechanical forces according to analysis based on global burden of disease data in 2017.

Neglected tropical diseases affect more people than the population of Europe

This group of conditions, which includes hookworm, sickens roughly one in seven people on the planet—a tally which dwarfs Europe's population of roughly 450 million. International cooperation and donations are helping to control some of these illnesses, which can be caused by parasites, viruses, and bacteria. They're all treatable or preventable, but primarily occur among poor, isolated communities that may not receive adequate care.

Caucasians are at the greatest risk of developing macular degeneration

A 2016 analysis across ethnic groups found, among other things, that white participants had the highest incidence of the disease, followed by Chinese, Hispanic, and Black participants. This study did not answer why that may be the case.

Why are kids increasingly diagnosed with myopia?

According to the World Health Organization, 40% of the world will have myopia—nearsightedness—by 2030. This NPR podcast episode details why people are being diagnosed with myopia at increasingly younger ages. Early onset myopia can lead to...

More than 5% of the world's population has disabling hearing loss

Disabling hearing loss is defined as hearing loss greater than 35 decibels in the better hearing ear. (For context, that means the sound of leaves rustling, at roughly 30 decibels, would be inaudible even to your better-hearing ear.) The World Health Organization's data suggests that more than 5% of the world's population has this level of loss requiring rehabilitation, which amounts to 430 million people—including 34 million children.

One in 10 adults worldwide has diabetes.

China reports the highest prevalence of hearing loss and South Africa reports the lowest

This conclusion comes from research published in 2025 that analyzed self-reported hearing loss and hearing aid use from long-term studies that covered 28 countries. Its findings included that the countries with the greatest prevalence of hearing loss (China, South Korea, Mexico, and Brazil) also had the lowest levels of hearing aid use.

Vector-borne diseases kill more than 700,000 people globally each year—and are growing

The diseases with the greatest potential to spread widely aren't the ones that quickly kill human hosts. Instead, the best hosts or reservoirs for vector-borne diseases would be chronically ill over the long term, increasing the likelihood that the pathogen could be transmitted to others.

What did people do before eyeglasses were invented?

An estimated two-thirds of the world's adults use a form of prescription glasses or contacts, proof spectacles were a godsend when they were invented in 1286 CE. But what did people do before that? Different tools were used for distinct vision problems, but some would use magnifying lenses, clear emeralds, and more. Watch this video for a historical explanation.

There are more than 1,400 listed clinical trials for macular degeneration

The US database of clinical trials listed more than 1,400 macular degeneration trials in early 2026. That doesn't mean every trial is recruiting, but it does indicate there is significant interest in this medical condition.

Hear what it's like to have malaria from a patient who suffered from the mosquito-borne disease.

Roughly 10% of the world's population is older than 65 (2023 data)

With recent advances in medicine, sanitation, and nutrition, expected lifespans have rapidly risen around the globe—resulting in a rapidly aging global population. The worldwide distribution has seen a nearly 600% jump in the population of people aged 65 and older.

View a map of countries with the safest and most dangerous drinking water

More than a quarter of the world's population lives in water-stressed countries, and a similar number use contaminated drinking water sources, which can lead to widespread disease, according to the World Health Organization. The Environmental Performance Index shows which countries have safe drinking water.

America's financial burden from dementia in 2025 was $781 billion

That figure, calculated by researchers at the University of Southern California, includes medical and long-term care costs, unpaid family and friend caretaking, lost productivity for patients and their families, and the economic loss in quality of life for patients and their families. In 2025, they estimate there were 5.6 million people living with dementia.

America's top causes of death are heart disease, cancer, accidents, and stroke

Heart disease killed more than 680,000 people in 2023 and cancer killed around 613,000 people that year. Both causes of death are far above the next leading cause of death—accidents, which numbered around 223,000. Provisional data for 2024 indicates the leading causes of death remained the same.

From 1970 to 2017, invasive species have caused $1.28T in damage globally

The costliest species were the Asian tiger and yellow fever mosquitoes ($149B), which arrived in the US from Asia and sub-Saharan Africa, respectively. The bulk of their damage came from their transmission of diseases such as Zika, chikungunya, and dengue. (Some readers may experience a paywall.)

Children under 5 account for 76% of all malaria deaths in Africa

The main hypothesis for why the disease hits this age group the hardest is that children this young have still-developing immune systems. Pregnant women and people with HIV/AIDS are also at higher risk of severe infection.

Treating black fever can result in a complication that spreads the deadly disease

Black fever, a deadly parasitic disease second only to malaria, threatens more than 1 billion people across more than 83 countries. Also known as kala-azar or visceral leishmaniasis, the disease is caused by parasites that spread through sandfly...

As deposits build up under the eye, the retina bends with macular degeneration

The retina bends due to the accumulation of proteins and other materials beneath it. That's considered the milder "dry" form of macular degeneration. Another form, called "wet" macular degeneration, is caused by abnormal blood vessels leaking fluid into the eye, which can rapidly affect central vision.

Roughly 1 in 125 people have autism spectrum disorder globally

The disorder has been increasingly diagnosed as its definition has grown broader and as clinicians have become more adept at identifying it—with some estimates suggesting the figures are much higher. These figures include people across the spectrum, some of whom live mostly independent lives, while others require life-long care and assistance.

Vizualize global debt by country

Global debt reached $226T by the end of 2020—the biggest one-year jump since World War II. This graphic compares the debt-to-GDP ratio of various countries.

We're in the middle of a decadeslong cholera pandemic

In 1961, the world's seventh recorded cholera pandemic started in South Asia, and it has continued through the decades. India and Bangladesh are at particular risk. This pandemic is driven partly by conflict, population displacement, extreme weather, and poor water infrastructure.

Data visualizations showing population growth around the world

This page presents data, charts, and analysis on changes in population growth around the world. Over the last few centuries, the human population has gone through an extraordinary change. In 1800, there were 1 billion people; today, there are more...

People with blue eyes appear to be at elevated risk of developing macular degeneration, perhaps because more light can penetrate their eyes.

Mapping the world's cell towers

Millions of cell towers around the world help connect the world's 8 billion people via cell phones and the Internet. But access to such coverage, while still expanding, is not equal. This data visualization depicts the world's many cell connections across a global map, revealing cell use hot spots and the world's many gaps in coverage.

Mosquitoes top the ranking of the world's deadliest animals.

Visualizing cause of death over time in America

As people age, their life expectancy decreases, but the timing and speed of this decline have evolved over the years. Check out this chart which shows the shift in various causes of death of Americans over the last few decades. Data from the...

More than 4,000 people died from cholera in 2023

This global health threat sickened more than half a million people in 2023 and killed 4,007 people. That's a 71% increase in deaths as compared to a year earlier. (Report only offered in PDF format.)

See this diverse list of vector-borne diseases

Human illnesses caused by parasites, viruses, and bacteria, and transmitted by a living organism—often small, bloodsucking ones like mosquitoes, ticks, and sandflies—are known as vector-borne diseases. That carrier is called a vector. These diseases disproportionately affect the poorest populations in tropical and subtropical areas.

Using brain implants to restore vision

Several companies are attempting to create brain-computer interfaces that skip over retinas and optic nerves to allow visual input to go straight to the brain, potentially restoring some sight to the blind. Clinical trial findings suggest restored sight is sparse and manifests differently than a sighted person might expect, appearing as specks of "light" clusters called phosphenes to help differentiate one's surroundings.

The World Bank’s population data bank

This website by the World Bank provides visualizations for demographic data from around the world. Specific demographic data, such as total population, can be viewed through maps, charts, and graphs. Results can be filtered by sex, country, or year....

The macula is a small area in the center of the retina

This part of the eye—roughly the bullseye of the back of the eye—is responsible for processing the central vision of the eye. Degradation of the macula, formally called macular degeneration, leads to symptoms including blurred vision, the need for brighter lighting, and difficulty recognizing faces. The condition doesn't affect peripheral vision, but if you lose central vision, you can still be considered blind.

More than 1 in 7 people worldwide have had Lyme disease

Research published in 2022 suggests that 14.5% of the world's population has contracted Lyme disease. Researchers arrived at that estimate by analyzing the presence of Lyme disease antibodies (indicating prior infection) across 89 studies conducted between January 1984 and December 2021. The works collectively included blood samples from more than 150,000 people. (Some user may encounter a paywall.)

How global conditions have improved over 200 years

In an era of 24-hour news, it can feel as if the world is on a perpetual downward spiral. This set of visualizations zoom out, and show how global living conditions have improved in recent centuries. The percentage of people living in extreme...

Usher Syndrome, a rare genetic disorder, causes progressive hearing and vision loss, and people with the condition sometimes eventually become deaf and blind.

Drug-resistant infections worldwide have increased by about 65% since 2000

Since 1990, antibiotic resistance has claimed at least one million lives annually and is projected to account for 39 million deaths between now and 2050 if current trends continue. The expanded use of antibiotics, particularly in agriculture, combined with a slowing pipeline of new drugs has led to the crisis.

See which countries have already reached their peak population, and when others will eventually reach theirs.

In a first, eye prosthesis has restored sight to macular generation patients

In a clinical trial, 27 of 32 participants with advanced macular degeneration regained enough vision to read books, food labels, and subway signs about a year after receiving a prosthetic retina device. This is the first device to restore functional vision to patients with incurable vision loss, though in this case they can only see in black and white, with no shades in between.

As of 2022, scientists estimate that 117 billion people have been born on Earth

Although no demographic data exist for more than 99% of the time humans have existed, this value can be estimated by tracking approximate population sizes over different periods and the birth rates within those periods. In 2022, about 6.8% of humans that have ever been born were alive.

1 in 4 people around the world don't have access to clean water

Poor water sanitation puts people at risk of acquiring this diarrheal infection. Cholera infections are on the rise due to extreme weather events and conflict. In recent years there have been cholera outbreaks in locations that hadn't seen the disease in many years, including Haiti.

Influenza infects up to a billion people worldwide each year

The World Health Organization estimates that seasonal influenza causes about 1B cases annually, including 3 to 5M severe illnesses and between 290,000 to 650,000 deaths.