Air pollution might worsen children’s vision

AI model: Short for artificial-intelligence model, it’s a particularly smart computer algorithm. Simple types of these models choose from a set of pre-selected to answer a user’s requests (perhaps to respond to a chat). More complex models may train on mountains of data to essentially figure out their own answers to potentially novel questions.

artificial intelligence: A type of knowledge-based decision-making exhibited by machines or computers. The term also refers to the field of study in which scientists try to create machines or computer software capable of intelligent behavior.

blood vessel: A tubular structure that carries blood through the tissues and organs.

cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells.

coauthor: One of a group (two or more people) who together had prepared a written work, such as a book, report or research paper. Not all coauthors may have contributed equally.

computer model: A program that runs on a computer that creates a model, or simulation, of a real-world feature, phenomenon or event.

correlation: A mutual relationship or connection between two variables. When there is a positive correlation, an increase in one variable is associated with an increase in the other. (For instance, scientists might correlate an increase in time spent watching TV with an increase in rates of obesity.) Where there is an inverse correlation, an increase in one value is associated with a drop in the other. (Scientists might correlate an increase in TV watching with a decrease in time spent exercising each week.) A correlation between two variables does not necessarily mean one is causing the other.

data: Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

disorder: (in medicine) A condition where the body does not work appropriately, leading to what might be viewed as an illness. This term can sometimes be used interchangeably with disease.

factor: Something that plays a role in a particular condition or event; a contributor. (in math) The numbers (or any algebraic expressions) that can divide another number (or expression) evenly, with no remainder. For example, 2 and 5 are factors of 10 (as 10 can be divided by 2 and give you 5, with no leftovers).  Ten’s other factors are 1 and 10.

function: The specific role some structure or device plays.

genetic: Having to do with chromosomes, DNA and the genes contained within DNA. The field of science dealing with these biological instructions is known as genetics. People who work in this field are geneticists.

high school: A designation for grades nine through 12 in the U.S. system of compulsory public education. High-school graduates may apply to colleges for further, advanced education.

immune: (adj.) Having to do with immunity. (v.) Able to ward off a particular infection. Alternatively, this term can be used to mean an organism shows no impacts from exposure to a particular poison or process. More generally, the term may signal that something cannot be hurt by a particular drug, disease or chemical.

link: A connection between two people or things.

machine learning: A technique in computer science that allows computers to learn from examples or experience. Machine learning is the basis of some forms of artificial intelligence (AI). For instance, a machine-learning system might compare X-rays of lung tissue in people with cancer and then compare these to whether and how long a patient survived after being given a particular treatment. In the future, that AI system might be able to look at a new patient’s lung scans and predict how well they will respond to a treatment.

myopia: The medical term for nearsightedness. An inability to focus on anything much more than an arm’s length away.

nearsighted: An inability to focus anything that isn’t nearby. It’s due to an elongation of the eyeball. Many factors can contribute to this inappropriate elongation, and so the cause of nearsightedness is still under debate.

nitrogen dioxide: A gas — often abbreviated as NO₂ — that has become an important pollutant in urban air. Most of this gas in the Earth’s lower atmosphere has been released by human activities. Gasoline- and diesel-fueled vehicles are among the most common sources of NO₂ in cities. Coal- and natural-gas-burning power plants also can emit regionally high amounts. This pollutant can cause breathing problems and aggravate lung-related diseases such as asthma. NO₂ is among pollutants that contribute to the formation of smog and acid rain.

ophthalmologist: A medical doctor who specialize in conditions and diseases affecting the eyes. They begin as general medical doctors and then get several additional years of training on diagnoses and treatment of problems affecting the eyes. Optometrists, in contrast, are doctors but are not trained as physicians (what in the United States are known as “medical” doctors).

organ: (in biology) Various parts of an organism that perform one or more particular functions. For instance, an ovary is an organ that makes eggs, the brain is an organ that makes sense of nerve signals and a plant’s roots are organs that take in nutrients and moisture.

oxidative stress: A condition in a living organism where more oxidative chemicals — broadly known as free radicals — are being formed or affecting cells than can be managed by the body’s antioxidant defense system. Some diseases or injuries increase the production of free radicals, leading to tissue damage.

particle: A minute amount of something.

retina: A layer at the back of the eyeball containing cells that are sensitive to light and that trigger nerve impulses that travel along the optic nerve to the brain, where a visual image is formed.

risk: The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. (For instance: Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.)

stress: (in biology) A factor — such as unusual temperatures, movements, moisture or pollution — that affects the health of a species or ecosystem. (in psychology) A mental, physical, emotional or behavioral reaction to an event or circumstance (stressor) that disturbs a person or animal’s usual state of being or places increased demands on a person or animal; psychological stress can be either positive or negative. (in physics) Pressure or tension exerted on a material object.

survey: To view, examine, measure or evaluate something, often land or broad aspects of a landscape. (with people) To ask questions that glean data on the opinions, practices (such as dining or sleeping habits), knowledge or skills of a broad range of people. Researchers select the number and types of people questioned in hopes that the answers these individuals give will be representative of others who are their age, belong to the same ethnic group or live in the same region. (n.) The list of questions that will be offered to glean those data.

system: A network of parts that together work to achieve some function. For instance, the blood, vessels and heart are primary components of the human body’s circulatory system. Similarly, trains, platforms, tracks, roadway signals and overpasses are among the potential components of a nation’s railway system. System can even be applied to the processes or ideas that are part of some method or ordered set of procedures for getting a task done.