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Ray Diagram

  1. Apr 11, 2008 #1


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    1. The problem statement, all variables and given/known data
    This is a follow on question. The first few questions ask about finding the numerical answer. The question that I am confused about and cannot do seem to do properly says:
    Complete the ray diagram to locate the position of the image shown on the retina when effective focal length of eye is [itex]0.020m[/itex].

    2. Relevant equations
    I was given the total power of the lens+cornea as [itex]56.0D[/itex]. I calculated the focal length by [itex]f = \frac{1}{P} = \frac{1}{56} = 0.02m[/itex] to 2dp.

    3. The attempt at a solution
    I attempted it and drew the focal points [itex]0.02m[/itex] from the center axis which is the lens+cornea axis. They had already provided an arrow for the Image on the retina but when I drew the diagram, it didn't meet on the grid but met outside the grid that they had provided.
  2. jcsd
  3. Apr 11, 2008 #2
    could you indicate roughly what is the ordering of these and their separation?
    retina, lens, focal point, image, object
  4. Apr 11, 2008 #3


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    Basically, the grid scale was 1 small square= 0.002m. The grid had 5x5 small boxes which made up one cm square.

    There is only a grid with an axis and we have to draw all the points ourself so I thought that I would need to draw the focal point 2 cm away from the y-axis.

    There isn't any detail about the separation. I assume you just have to draw it approximately, showing how a real image is formed?
  5. Apr 11, 2008 #4
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