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A limbal ring is a dark ring around the
The limbal ring is thought to contain corneal epithelium stem cells. Diseases involving a limbal stem cell deficiency are associated with blindness, as those with such deficiencies are "unable to maintain a stable corneal surface." Transplantation of limbal stem cells is a promising therapy for limbal stem cell deficiency.
A limbal ring is a dark ring around the iris
Iris most often refers to:
*Iris (anatomy), part of the eye
*Iris (mythology), a Greek goddess
* ''Iris'' (plant), a genus of flowering plants
* Iris (color), an ambiguous color term
Iris or IRIS may also refer to:
Arts and media
Fictional ent ...
of the eye, where the sclera
The sclera, also known as the white of the eye or, in older literature, as the tunica albuginea oculi, is the opaque, fibrous, protective, outer layer of the human eye containing mainly collagen and some crucial elastic fiber. In humans, and so ...
meets the cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...
.Johnson and Johnson Vision Care Inc. Tinted contact lenses with combined limbal ring and iris patterns. US7246903B2. United States Patent and Trademark Office, July 24, 2007. http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&p=1&u=/netahtml/PTO/srchnum.html&r=1&f=G&l=50&d=PALL&s1=7246903.PN. It is a dark-colored manifestation of the corneal limbus
The corneal limbus (''Latin'': corneal border) is the border between the cornea and the sclera (the white of the eye). It contains stem cells in its palisades of Vogt. It may be affected by cancer or by aniridia (a developmental problem), among ...
resulting from optical properties of the region. The appearance and visibility of the limbal ring can be negatively affected by a variety of medical conditions concerning the peripheral cornea. It has been suggested that limbal ring thickness may correlate with health or youthfulness and may contribute to facial attractiveness. Some contact lens
Contact lenses, or simply contacts, are thin lenses placed directly on the surface of the eyes. Contact lenses are ocular prosthetic devices used by over 150 million people worldwide, and they can be worn to correct vision or for cosmeti ...
es are colored to simulate limbal rings.
Youth, health, and attractiveness
Both health and age are positively correlated with a prominent limbal ring. For instance, a darker limbal ring tends to be found more attractive than the absence of a limbal ring, suggesting that both sexes "use the limbal ring as a probabilistic indicator of reproductive fitness". Furthermore, limbal rings appear to be most noticeable "for individuals relatively free from chronic health issues".
The limbal ring is thought to contain corneal epithelium stem cells. Diseases involving a limbal stem cell deficiency are associated with blindness, as those with such deficiencies are "unable to maintain a stable corneal surface." Transplantation of limbal stem cells is a promising therapy for limbal stem cell deficiency.
See also
*Circle contact lens
A circle contact lens, also known as a big eye contact lens and circle lens, is a cosmetic (non-corrective and decorative) contact lens that makes the eye's iris appear larger. It has become a trend throughout East, South and Southeast Asia and i ...
* Limbus sign
* Corneal limbus
The corneal limbus (''Latin'': corneal border) is the border between the cornea and the sclera (the white of the eye). It contains stem cells in its palisades of Vogt. It may be affected by cancer or by aniridia (a developmental problem), among ...
References
External links
Eye color {{eye-stub