• Question: Why are some peoples sight weaker to others. My eyesight isnt that good why is this?

    Asked by the arch bishop of banter to Rebecca, Josh, Chris on 17 Jun 2015.
    • Photo: Rebecca Dewey

      Rebecca Dewey answered on 17 Jun 2015:

      Eyesight depends on the shape of the eyeball (how far light has to travel from the pupil to the retina (or more specifically, how far from the pupil to the lens, how far through the lens, and how far from the lens to the retina). All this geometry affects how good (how “sharp”) the image is. Also, the health of the lens and the retina affect eyesight. If you wear glasses, I would guess it is because your eyeball is a little bit wider between the lens and the retina. This means that the image is focussed too far forward (a little bit nearer the middle of the eyeball) rather than on the retina. Your glasses help de-focus the light a bit so that your lens can make the image in the right place. As people get older, their vision gets longer so you might find you don’t need glasses any more when you’re a bit older!

Comments