Journal 2

JOURNAL ENTRY WEEK 2

Investigate the two types of sight defect- long-sightedness and short sightedness.

Find the following information:

1. what causes the defect
2. the symptoms displayed
3. propose what sort of lens may be used to correct each vision.

1a-Hyperopia- The causes of hyperopia are typically genetic and involve an eye that is too short or a cornea that is too flat, so that images focus at a point behind the retina.

http://www.docshop.com/education/vision/refractive-errors/hyperopia/

  b-syptoms displayed are trouble seeing objects that are close up. In some cases, they may not recognize that they have a vision problem, but will notice that their eyes become tired or sore during such activities as reading or writing.

http://www.docshop.com/education/vision/refractive-errors/hyperopia/

  c-the lens that can correct hyperopia is wearing convex lenses which bend light more so the focus point of the image is brought forward onto the retina.

2a-Myopia-Usually develops in children or young teenagers. You are more likely to develop myopia if it runs in your family. Temporary short-sightedness, called pseudomyopia, can be caused by certain diseases or drugs.

  b-Trouble seeing objects that are far away.

http://www.webmd.com/eye-health/tc/nearsightedness-myopia-symptoms

  c- the lens that can correct myopia are concave leses that move the focus point of the image back onto the retina.

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