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OPTO 495

Midterm Exam I

Date: 5/20 /1429 correspond 5/ 25 /2008


           Student Name:

           Student Number:

A- Answer with T/ F and correct the wrong answer


1- For the LVE to be objective:

            a- You should attempt to encourage the patients as much as possible.T       F


b- The rhythm of the examination should be as fast as possible so the pt will not be frustrated / kept low so that the patient can follow instruction.                                                                           T          F


c- Prints of near point card should be clear with different contrasts / and of good contrast.                                                                           T          F


2- During the LVE using the retinoscopy, it is better to start with the poorer eye, then binocularly/ binocularly or with the better eye then examine the poorer eyelater.                                                                                                    T          F

3- In order to improve vision and optimize performance for the low vision pts, magnification combined with other strategies should be used.                        T          F


B- Short Answer

1- What is the magnification required to improve vision from 3/30 to 6/20                      5points 

Magnification required =   required VA

                                           present VA


            = 3/30     =   30/3 x 6/20 =  3X


 2- Using the trial frame in the LVE has good advantages for the pt and instructor, briefly explain                                                                                                            

 Trial frame of trial lens set are preferred for the L.V. examination.

            They enable the patient to fixate eccentrically and for the examiner to observe the manner in which the patient in fixating e.g. nystagmus, squinting, head tilt.




OPTO 271

Midterm Exam 1

Date: 3/30/1429 correspond 4/ 7/2008



 Student Name:

Student Number:

 Q 1- Complete the sentences.                                              

a-    a-  The visible spectrum of light has a wavelength range of 380 to 780 µm.

 b-      V  =  f l, Means;   V for light is constant, longer wavelengths mean shorter frequencies, and vice versa.

 c-      The speed of light is 186, 000 miles per second or as in physics, 3.0 X 108 meters per second.

 d-     Light is an electromagnetic radiation just like radio waves, x-rays, microwaves, infrared rays, ultraviolet rays and gamma rays.


Short Answer  

 Q2- light photons can behave both as particles, and as waves. Briefly, explain this phenomenon

         It sometimes advantageous to assume that light photons (light atoms if you like) travel in straight lines, but vibrate in a direction 900 from the direction of movement of the light ray.

         At other times, it is advantageous to assume that light photons behave as waves, so that at any one time, they do not have a definite position but are spread out with a certain probability distribution.

 Q 3- What is the Refraction and Refractive Index? (6 points)

        Refraction is the change in the direction of a light ray when it passes from one medium to another. If the second medium is denser than the first, the ray is bent towards the normal.

        Refraction takes place because of the change in velocity of light as it passes from one medium to another. The ratio of the velocities is called refractive index. 

     V1/ V2   =   n2/n1   = refractive index of the second medium relative to the first. 


        Index of refraction = Speed of light in air

                                          Speed of light in substance 



OPTO 394

Midterm Exam 1

Date: 3/30/1429 correspond 4/ 7/2008


  Student Name:

Student Number:

  Q1- Fill In Blanks                                                                    

a-      The elderly population as a group are richer than the general population.


b-      In the U.S. As of 1988, the net worth of elderly households was more than twice the national average of $ 35,800.


c-       The majority of elderly pts in medically advanced countries are healthy, functionally independent members of society.

 Short Answer

Q1- Vision Screening and other services such as referrals and public education should be carried out to the elderly population in the morning. Briefly explain.

        A typical screening would include ocular and systemic health history, V.A. at 6 metres and at near distances (typically determined by the patient), pupil evaluation, tonometry and direct ophthalmoscopy.

        A short interview should then be held with the patient to discuss normal and abnormal findings and the recommended line of action.

Referrals of older patients to medics, dentists. And podiatrists.

  It may also help to distribute pamphlets to older people, giving them necessary information about how aging affects their vision and what can be done to minimize these effects.

         Such knowledge/education may, in some countries, be gained at universities or community colleges or from reading publications that cover issues affecting the elderly. Public education seminars to the elderly.

        If the optometrist is running a full geriatric practice (or has specific days for older patients), it may be wise to employ an older person (50 years or more) to receive the elderly patients, assist them with putting down preliminary information, and generally chat with them before the patient is seen by the doctor.


  Q2- The tear film declined by about one half from age 8 to age 80. What are the causes of this deficiency?

         Deficiencies in the aqueous, oily, and to a lesser extent, the mucin layer of the tear film have all been indicated in decrease of tear film stability.

        Less forceful blinks (which occur in the elderly because of reduced lid-muscle ton) and blinking less when concentrating are also factors indicated in the destabilization of the tear film.





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