Squinting is the action of looking at something with partially closed eyes. Squinting is most often practiced by people who suffer from refractive errors of the eye who either do not have or are not using their

glasses Glasses, also known as eyeglasses (American English), spectacles (Commonwealth English), or colloquially as specs, are vision eyewear with clear or tinted lenses mounted in a frame that holds them in front of a person's eyes, typically u ...

. Squinting helps momentarily improve their

eyesight Visual perception is the ability to detect light and use it to form an image of the surrounding environment. Photodetection without image formation is classified as ''light sensing''. In most vertebrates, visual perception can be enabled by ph ...

by slightly changing the shape of the

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

to make it rounder, which helps light properly reach the fovea. Squinting also decreases the amount of

light Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400– ...

entering the eye, making it easier to focus on what the observer is looking at by removing rays of light which enter the eye at an angle and would need to otherwise be focused by the observer's faulty

lens A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements'') ...

and

cornea The cornea is the transparency (optics), transparent front part of the eyeball which covers the Iris (anatomy), iris, pupil, and Anterior chamber of eyeball, anterior chamber. Along with the anterior chamber and Lens (anatomy), lens, the cornea ...

Pinhole glasses Pinhole glasses, also known as stenopeic glasses, are eyeglasses with a series of pinhole-sized perforations filling an opaque sheet of plastic in place of each lens. Similar to the workings of a pinhole camera, each perforation allows only a ver ...

, which severely restrict the amount of light entering the cornea, have the same effect as squinting. It is a common belief that squinting worsens eyesight. However, according to

Robert MacLaren Robert E. MacLaren (born 14 November 1966) is a British ophthalmologist who has led pioneering work in the treatment of blindness caused by diseases of the retina. He is Professor of Ophthalmology at the University of Oxford and Honorary Profes ...

, a

professor Professor (commonly abbreviated as Prof.) is an Academy, academic rank at university, universities and other tertiary education, post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin ...

ophthalmology Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a ...

at the

University of Oxford The University of Oxford is a collegiate university, collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the List of oldest un ...

, this is nothing more than an

old wives' tale An "old wives' tale" is a colloquial expression referring to spurious or superstitious claims. They can be said sometimes to be a type of urban legend, said to be passed down by older women to a younger generation. Such tales are considered super ...

: the only damage that can be caused by squinting for long periods is a temporary

headache A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...

due to prolonged

contraction Contraction may refer to: Linguistics * Contraction (grammar), a shortened word * Poetic contraction, omission of letters for poetic reasons * Elision, omission of sounds ** Syncope (phonology), omission of sounds in a word * Synalepha, merged ...

of the

facial muscles The facial muscles are a group of striated skeletal muscles supplied by the facial nerve (cranial nerve VII) that, among other things, control facial expression. These muscles are also called mimetic muscles. They are only found in mammals, alth ...

. Squinting is also a common involuntary reflex, especially among people with light colored eyes, during

adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the p ...

to a sudden change in lighting such as when one goes from a dark room to outdoors on a sunny day to avoid

pain Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...

or discomfort of the eyes. The

pupillary light reflex The pupillary light reflex (PLR) or photopupillary reflex is a reflex that controls the diameter of the pupil, in response to the intensity ( luminance) of light that falls on the retinal ganglion cells of the retina in the back of the eye, t ...

caused by adjustment to light takes around five minutes in people with healthy eyes, so squinting and pain after that could be a sign of

photophobia Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom, photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence o ...

. In film, squinting often denotes mystery. Many eye expressions convey specific feelings, but squinting is more ambiguous, as it can signal multiple emotions, such as suspicion, toughness, and desire.

Clint Eastwood Clinton Eastwood Jr. (born May 31, 1930) is an American actor and film director. After achieving success in the Western (genre), Western TV series ''Rawhide (TV series), Rawhide'', Eastwood rose to international fame with his role as the "Ma ...

built his career out of mastering squinting, expressing everything from terse stoicism as the

Man With No Name The Man with No Name () is the antihero character portrayed by Clint Eastwood in Sergio Leone's "''Dollars Trilogy''" of Italian Spaghetti Western films: '' A Fistful of Dollars'' (1964), '' For a Few Dollars More'' (1965), and '' The Good, t ...

in ''

The Good, the Bad and the Ugly ''The Good, the Bad and the Ugly'' (, literally "''The good, the ugly, the bad''") is a 1966 Italian epic spaghetti Western film directed by Sergio Leone and starring Clint Eastwood as "the Good", Lee Van Cleef as "the Bad", and Eli Wallach a ...

'' to romantic desire as Robert Kincaid in ''

The Bridges of Madison County ''The Bridges of Madison County'' (also published as ''Love in Black and White'') is a 1992 best-selling Romance novel, romance novel by American writer Robert James Waller that tells the story of an Italian-American World War II war bride livi ...

''.

Manohla Dargis Manohla June Dargis ( ) is an American film critic. She is the chief film critic for ''The New York Times''. She is a five-time finalist for the Pulitzer Prize for Criticism. Career Before being a film critic for ''The New York Times'', Dargis ...

once quipped that "eyes may be windows to the soul, but men like Eastwood like to keep the shades partly drawn."

References

{{Reflist category:Eye Facial expressions