a. rarely contains IgA
b. newborn babies normally do not produce tears in the first day
c. blinking is important in the transport of tears to puncta
d. there is diurnal difference in lacrimal secretion
e. production decreases with age

2. Ocular movement:

a. function of saccadic movement is to place object of interest on fovea 
    rapidly
b. velocity of saccadic movement can be up to 400 degrees per second
c. smooth pursuit allow image of moving object to stay near fovea
d. latency of saccadic movement is usually 200 millisecond
e. the brain-stem reticular formation is associated with smooth pursuit

3. Tear film:

a. contains a thin oily layer
b. aqueous layer is 10um thick
c. deficiency in conjunctival secretions could produce dry eye symptoms 
    even aqueous tear is adequate
d. 10-25% of the total tears secreted are lost by evaporation
e. tear production decreases with timolol

4. Cornea:

a. water content at a level of 75-80% of its weight
b. drugs have to be water soluble to cross the epithelium rapidly
c. transparent as a result of tightly and randomly packed fibrils
d. capillaries extend into the cornea 1 or 2 mm beyond the limbus
e. contains glycosaminoglycans

5. The intra-ocular pressure blood vessels:

a. the pressure in the ophthalmic artery is about 100mmHg
b. the choroidal and retinal capillaries lack precapillary sphincters
c. the choroidal flow increases with any rise in intraocular pressure
d. complete obstruction fo the central retinal artery for more than one hour 
    may lead to permanent total blindness
e. the eye receives all its blood from the internal carotid artery

6. Visual acuity:

a. for ordinary illuminations a pupil diameter of 2.3mm is the optimum 
b. under photopic conditions, acuity deteriorates on passing from the retinal 
    foveal to the periphery
c. under scotopic conditions acuity increases with progressive dark 
    adaptation
d. T is generally easier letter to read than L
e. is not affected by the intelligence

7. Intraocular pressure:

a. increases with age
b. is not correlated with heart rate
c. shows diurnal variation
d. decreases during sleeping
e. is not affected by general anaesthesia

8. The cornea:

a. contains 78% of water
b. enzymes of the tricarboxylic acid cycle are present in the corneal 
    epithelium alone
c. water can diffuse freely through the cornea in both directions
d. mucopolysaccharides form 8% of the corneal dry weight
e. keratin sulphate forms 25% of its dry weight

9. The saccadic system system:

a. is generated in the occipital region
b. has a latent period is about 400msec
c. the velocity of movement is of the order of 350 degrees per second
d. is depressed after taking sedatives
e. is related to the activity in the reticular activating system

10. The following are true about accommodation:

a. the reaction time for the reflex to occur is about 0.15 seconds
b. the central zone fo the anterior surface of the lens becomes more 
    convex
c. the stimulus to accommodation is a blurred retinal image
d. the range of accommodation is proportional to the amplitude of 
    accommodation
e. the amplitude fo accommodation is about 5 dioptres at the age of 60

 

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