Page 39 - The Book Pi in eye
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Pi in eye

                                   Also, you  will need  to bring  your glasses and/or contact  lenses.
                                You may need to bring sunglasses, in case the doctor will instill eye
                                drops to dilate your pupils. Enlarged pupils will make you very light
                                sensitive as well as causing blurry vision for a few hours.

                                   Eye Examination Day:

                                   During the examination, the doctor may look at different factors.
                                The  appointment  may  last  over  one  hour.  The  doctor  may  use
                                different forms of tests to make sure that your eyes are healthy, and in
                                good condition. You may wonder, “What does the doctor look at?”
                                   The doctor checks for any of the following conditions:
                                        Myopia (nearsightedness)
                                        Hyperopia (farsightedness)
                                        Presbyopia
                                        Glaucoma
                                        Cataracts, dryness, etc.

                                   Determining the Health of Your Eyes:

                                   The doctor can use the Visual Acuity Test, which helps understand
                                the clarity of your vision. You may have heard of people saying that
                                they  have  20/20  vision  and  this  is  what  the  test  determines.  The
                                doctor will use the familiar Snellen chart, which contains a series of
                                black letters that vary from big to small font, put onto a white screen.
                                   The results from the visual acuity test are expressed as 20/20 or
                                20/40. The first number expresses the fixed distance of twenty feet at
                                which  the  test  is  conducted.  The  second  number  is  the  distance  a
                                person with perfect vision can see the same letter from. For example,
                                if  your  visual  acuity  is  at  20/40,  then  whatever  you  are  seeing  at
                                twenty feet a person with perfect vision can see at forty feet. If your
                                vision  is  20/80  your  vision  is  one-fourth  as  good  as normal.  At
                                20/200 a person is considered legally blind.

                                   Axial length:
                                        Laser  biometry-  IOL  Master  or  Lenstar  measures  the
                                          distance  from  the  corneal  vertex  to  the  retinal  pigment
                                          epithelium   employing   a   light   beam.  This   allows   for
                                          accurate measurements of eye length. Both the instruments


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