i-GO Overnight Vision Correction (OVC) contact lenses are only worn at night. They gently reshape the curvature of the eye while sleeping to give crisp clear natural vision during waking hours. i-GO lenses are suitable for short-sighted people (those who can't see long distance) with a prescription up to -5.00D with -1.50 of astigmatism, and are exclusively available through qualified i-GO accredited opticians.