Crossword clues for near-sightedness
near-sightedness
Wiktionary
n. (alternative spelling of nearsightedness English)
Wikipedia
Near-sightedness, also known as myopia, is a condition of the eye where light focuses in front, instead of on the retina. This causes distant objects to be blurry while close objects appear normal. Other symptoms may include headaches and eye strain. Severe near-sightedness increases the risk of retinal detachment, cataracts, and glaucoma.
The underlying cause is believed to be a combination of genetic and environmental factors. Risk factors include doing work that involves focusing on close objects, greater time spent indoors, and a family history of the condition. It is also associated with a high socioeconomic class. The underlying mechanism involves the length of the eyeball being too long or less commonly the lens being too strong. It is a type of refractive error. Diagnosis is by eye examination.
There is tentative evidence that near-sightedness can be prevented by having young children spend more time outside. This may be related to natural light exposure. Near-sightedness can be corrected with eyeglasses, contact lenses, or surgery. Eyeglasses are the easiest and safest method of correction. Contact lenses can provide a wider field of vision; however are associated with a risk of infection. Refractive surgery permanently changes the shape of the cornea.
Near-sightedness is the most common eye problem and is estimated to affect 1.5 billion people (22% of the population). Rates vary significantly in different areas of the world. Rates among adults are between 15 and 49%. Rates are similar in males and females. Among children it affect 1.2% of rural Nepalese, 4% of South Africans, 12% of Americans, and 37% in some large Chinese cities. Rates have increased since the 1950s. Uncorrected near-sightedness is one of the most common causes of vision loss globally along with cataracts, macular degeneration, and vitamin A deficiency.
Usage examples of "near-sightedness".
When a lady, in a delicate and costly summer garb, with a floating veil and gracefully swaying gown, and, altogether, an ethereal lightness that made you look at her beautifully slippered feet, to see whether she trod on the dust or floated in the air—when such a vision happened to pass through this retired street, leaving it tenderly and delusively fragrant with her passage, as if a bouquet of tea-roses had been borne along—then again, it is to be feared, old Hepzibah's scowl could no longer vindicate itself entirely on the plea of near-sightedness.