Study Guide

• Acuity& Color blindness- Acuity is referred to as 20/20 vision, which means the eye can see an object 20 feet away clearly. The cornea is the clear transparent covering of the eye. Each of these refractive errors is discussed individually. Myopia is nearsighted. Hyperopia is farsightedness. Color blindness is the inability to distinctly differentiate colors of the spectrum. Defects in color vision are either congenital, inherited, acquired through disease or injury. The ability to distinguish colors depends on the cones of the retina, which react to light and permit us to see shades of red, green, and blue.

• Grave’s Disease- is the most common form of hyperthyroidism, it is an autoimmune disorder, and antibodies produced by the immune system stimulate the thyroid to produce too much thyroxine. Disease that results from an overactivity of the thyroid gland, can result in a crisis situation, also call hyperthyroidism.

Treatment & Tests

• Eye lavage&instillation- it is necessary to remove foreign substances or chemicals. Eye irrigation requires the use of sterile technique and equipment. Check irrigation solution 3 times before administering. Instilling eye medications may be one of your duties. Only ophthalmic or optic medications can be used in the eye, and they must be sterile. Place dropper about ½ inch above the eyeball with the dominant hand. Insert proper drops to the center of the conjunctiva.

• Ishihara Test- is printed in either card or booklet form with single color-dot illustration containing a number or curved lines and shapes.

• Snellen eye chart-snellen charts place the largest symbols on the top line, and each line after is of decreasing size. The person with normal vision will be able to read the top like at 200 feet. A result of 20/20 vision means that a person with normal distance acuity could read that line at a distance of 20 feet. Abbreviation for the right eye is OD, for the left eye is OS, and for both eyes is OU.

• Tonometry-Measurement of the intraocular pressure of the eye using a tonomter to check for glaucoma. An air puff tonometer records the cornea’s resistance to pressure.

• Vitrectomy –surgical procedure for replacing the contents of the vitreous chamber of the eye.

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