Myopia is a condition where the eye’s lens makes light focus before it reaches the retina so that the retina sees a blurred image. Night myopia is where this happens in low light conditions and can affect even those who have perfect daytime vision. As the light fades in the evening there is not enough to help us focus clearly and consistently on distant objects until, when it is dim enough, the eye’s focussing system comes to rest at about 1-1.5 metres ahead. This is entirely due to the low light levels and happens to those who have perfect daytime vision so, as you can imagine, those who are shortsighted during the day will suffer the effects of night myopia even more at night. The blurring effect is accentuated by the natural pupil enlargement that happens in low light.
So, should we wear special night myopia spectacles to correct this? Thankfully this is not necessary except in very special circumstances. When we drive at night there is generally enough light from street lamps and car headlights to prevent consistent night myopia. However, all drivers should drive more cautiously and use appropriate lighting, should use their daytime distance spectacles and take special note of kerb edges and lane markings. Obviously, drivers should not use tinted lenses at night because they further reduce the amount of light entering the eye.Back