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ACTIVITIES:
Light Talk
Forum: Shedding Light
Topic: Nightblindness
Topic Posted by: Belinda Miller (bmill6217@netscape.net )Date Posted: Sun Nov 14 10:53:38 US/Eastern 1999
Topic Description: Questions: What is nightblindness? Is it caused by the rods in the eye becoming less sensitive? What can we do about it? Why are some people's pupils larger than others?
Previous message
Posted by: Anita Greenwood (Anita_Greenwood@uml.edu )
Organization:UMass Lowell
Date posted: Fri Nov 19 21:16:17 US/Eastern 1999
Subject: Night Blindness
Message:
Night blindness is caused by a deficiency in vitamin A that is needed to produce the pigment found in rods (Rhodopsin). Rhodopsin is the pigment responsible for absorbing the photons of light energy. So the rods are less sensitive because they exhibit a reduced rate of regeneration of rhodopsin following exposure to light, i.e., delayed dark adaptation. However, some individuals have Congenital Stationary Night Blindness - a decreased sensitivity to light. One is born with this disorder (a genetic mutation) and it will neither improve nor get progressively worse.
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| Belinda Miller | Sun Nov 21 17:04:47 US/Eastern 1999 | ||
| Karen Kinyon | Sat Dec 11 16:05:27 US/Eastern 1999 | ||
| lynn | Thu Dec 23 21:22:32 US/Eastern 1999 | ||
| Zhantti | Sat Jan 26 5:40:44 2002 | ||
| salahudin | Sat Sep 24 2:38:54 2005 |
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