Eye Health Facts
Can I get bifocal contact lenses?
Multifocal contact lenses are available, with the lens varying in strength from the centre to the edge.
They work in a different way to bifocal or progressive glasses - instead of moving your eyes to look through a different section of the lens, with multifocal contact lenses light at different focusses is available at any point of gaze. Your visual system then figures out, somehow, which to ignore and which to give attention to.
See here also for other ways contact lenses can be used to correct vision for close work.
Eye Health Facts
Seeing in the dark
Vision in the dark continues to improve for about 30 minutes after being in bright light, as our eyes switch over from the colour-rich, crisp vision of daylight to the less crisp but more sensitive vision of night.
Once the eyes are adapted to dark, their most sensitive area is off to one side of 'straight ahead', making it possible to sense something out of the corner of your eye that disappears when you look straight at it.
Retinal degenerations, a genetic condition called retinitis pigmentosa, and Vitamin A deficiency can all reduce night vision.