Estimated read time: 2-3 minutes
This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.
ATLANTA, Georgia (CNN) — Tod Purvis and his brother Justin knew that they were going blind. Both had been diagnosed with choroideremia, a rare genetic disorder that causes progressive vision loss and eventually leads to complete blindness.
So six years ago, the brothers went on a road trip across the United States. A documentary about their journey, "Driving Blind," was released this year after winning awards at independent film festivals in 2013.
On the documentary's website, the filmmakers had this to say:
"We started filming under the impression that Tod and Justin had at least half of their eyesight left. It is revealed at the end that their eyesight was much much worse, and in truth the trip or film would have never happened had we knew they would in fact be driving blind. Justin was declared legally blind at the conclusion of the trip."
Tod Purvis took to the Internet community Reddit on Sunday to conduct an AMA (Ask Me Anything) about their trip, the documentary and choroideremia.
The most beautiful place they visited? Devil's Tower in Wyoming, Purvis said.
The second? Glacier Park in Montana.
"We took the trip to put the memories in our brain where we could always call them up even if we completely lost our sight," Purvis posted.
Choroideremia affects approximately 1 in every 50,000 people, according to the Choroideremia Research Foundation. It primarily occurs in males and starts in early childhood. It is caused by a gene mutation and is passed on to children via the X chromosome, according to the National Institutes of Health.
"Without the protein produced by the CHM gene, pigment cells in the retina of the eye slowly stop working, then die off," according to NLO, a center for eye research at the University of Oxford. "As the disease progresses, the surviving retina gradually shrinks in size, reducing vision."
Purvis said that his sight is down to about 50% but had difficulty describing what losing it was like to Reddit users.
We took the trip to put the memories in our brain where we could always call them up even if we completely lost our sight.
"It's hard to describe nothing. It's not black, it's like if you were looking through a tunnel, and the walls of the tunnel were made of mirrors and it reflected what was at the end of the tunnel."
Purvis wrapped up the AMA after more than 600 comments, never wavering from the documentary's main message:
"No matter what your situation ... live your life to the fullest."
The-CNN-Wire ™ & © 2014 Cable News Network, Inc., a Time Warner Company. All rights reserved.