Night's fears

IT’S not uncommon for a young child to be afraid of the dark, but on rare occasions it could be a tip-off to an unusual vision problem – congenital night blindness.  

“Everyone has difficulties seeing when room lights are switched off, but most people’s eyes adjust and a degree of vision returns after 10 minutes or so. For those with night blindness, this adjustment either does not happen or happens to only a limited degree,” says Ruth Hamilton, co-author of a report on the problem in the Jan 25 issue of the British Medical Journal. A profound fear of the dark may be the result, she says.