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Light Talk
NetForum - Message Replies
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?
Original 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.
Reply:
Subject: Nightblindness
Reply Posted by: Belinda Miller
(bmill6217@netscape.net
)
Date Posted: Sun Nov 21 17:04:47 US/Eastern 1999
Message:
Thanks for the information. The people in my group as well as my mother will be greatful for the information.
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