Light Talk

NetForum - Message Replies

Forum: Shedding Light

Topic: Nightblindness

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.

Subject: nightblindness
Reply Posted by: Karen Kinyon (K_Kinyon@wetn.pbs.org )
Date Posted: Sat Dec 11 16:05:27 US/Eastern 1999
Message:
In reference to being less able to see at night as one ages.....Does that mean if I take a vitamin A supplement or increase intake of foods that contain vitamin A I might have less difficulty with night driving?