Cataracts

How artificial tanning can lead to melanoma

Young women may be up on the latest fashions and trends as they prepare for prom season. But what many don't know is that the tan that looks oh-so-good with their dress may be the first step toward skin cancer.

May 01, 2015
popularity 48 comments 0

France moves to ban sunbed adverts, access for kids

France's parliament approved a draft law Friday banning advertising for artificial tanning beds and salons, and prohibiting people under 18 from using to the popular yet potentially dangerous ultraviolet technology.

Apr 03, 2015
popularity 5 comments 0

Alcohol study yields surprising results

The mortality of alcohol dependent patients in general hospitals is many times higher than that of patients without alcohol dependency. In addition, they die about 7.6 years earlier on average than hospital patients without ...

Apr 02, 2015
popularity 6 comments 0

Carnival game mimics eye growth

The motion of coins in a "Penny Pusher" carnival game is similar to the movement of cells in the eye's lens, as described in a new study published in Investigative Ophthalmology & Visual Science (IOVS). This new insight m ...

Mar 26, 2015
popularity 6 comments 0

A cataract is a clouding that develops in the crystalline lens of the eye or in its envelope (lens capsule), varying in degree from slight to complete opacity and obstructing the passage of light. Early in the development of age-related cataract, the power of the lens may be increased, causing near-sightedness (myopia), and the gradual yellowing and opacification of the lens may reduce the perception of blue colors. Cataracts typically progress slowly to cause vision loss, and are potentially blinding if untreated. The condition usually affects both eyes, but almost always one eye is affected earlier than the other.

A senile cataract, occurring in the elderly, is characterized by an initial opacity in the lens, subsequent swelling of the lens and final shrinkage with complete loss of transparency. Moreover, with time the cataract cortex liquefies to form a milky white fluid in a Morgagnian cataract, which can cause severe inflammation if the lens capsule ruptures and leaks. Untreated, the cataract can cause phacomorphic glaucoma. Very advanced cataracts with weak zonules are liable to dislocation anteriorly or posteriorly. Such spontaneous posterior dislocations (akin to the historical surgical procedure of couching) in ancient times were regarded as a blessing from the heavens, because some perception of light was restored in the cataractous patients.

Some children develop cataracts, called congenital cataracts, before or just after birth; these are usually dealt with in a different way to cataracts in adults.

Cataract derives from the Latin cataracta meaning "waterfall" and that from the Greek καταράκτης (kataraktēs) or καταρράκτης (katarrhaktēs), "down-rushing", from καταράσσω (katarassō) meaning "to dash down" (from kata-, "down"; arassein, "to strike, dash"). As rapidly running water turns white, the term may later have been used metaphorically to describe the similar appearance of mature ocular opacities. In Latin, cataracta had the alternate meaning "portcullis" and it is possible that the name passed through French to form the English meaning "eye disease" (early 15c.), on the notion of "obstruction". Early Persian physicians called the term nazul-i-ah, or "descent of the water"—vulgarised into waterfall disease or cataract—believing such blindness to be caused by an outpouring of corrupt humour into the eye.

This text uses material from Wikipedia licensed under CC BY-SA

Latest Spotlight News

The coming merge of human and machine intelligence

For most of the past two million years, the human brain has been growing steadily. But something has recently changed. In a surprising reversal, human brains have actually been shrinking for the last 20,000 ...

How the brain makes decisions

Some types of decision-making have proven to be very difficult to simulate, limiting progress in the development of computer models of the brain. EPFL scientists have developed a new model of complex decision-making, ...