• Question: How do glasses help you see? (as a fellow member of the glasses community, I was thinking how clever it is to be able to match them to your eyes!)

    Asked by fierylittle1 to Kate, Kieren, Nicola, Rowena, Roy on 14 Mar 2014.
    • Photo: Rowena Fletcher-Wood

      Rowena Fletcher-Wood answered on 14 Mar 2014:

      Glasses are basically very clever magnifying glasses. Tht focus at certain distances by making them a certain amount magnifying and different shapes and thicknesses. Opticians match them to our eyes by trial and error -making clever guesses and then narrowing them down to what suits you best. Contact lenses are similar but the differences between them are smaller because they are closer to your eyes and curved by your eyes.

    • Photo: Kate Nicholson

      Kate Nicholson answered on 14 Mar 2014:

      They bend the light so when it goes through the lens in your eye (that either over bends it or under bends it) it will fall exactly on the receptors at the back of your eyeball. We match them so well because we understand what shapes to cut the glass (or more often plastic) to bend the light in just the right amount and direction.

    • Photo: Nicola Rogers

      Nicola Rogers answered on 15 Mar 2014:

      If you can’t see well without glasses – the main problem is that the lens in your eye focuses parallel rays of light to a point, but this focal point occurs either too close to your lens or too far away from your lens, that the light is defocussed on your retina – glasses just add another lens infront of your eye to either increase the refraction or reduce the total bending of the light to move the focal point so that you can see sharp images

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