Chp 46: #2 Assessment of Eye and Vision

Which finding does the nurse consider abnormal while assessing a patient's pupils? Pupils are round in shape. Difference in size of the pupils. Diameter of each pupil is 3.5 mm. Pupils constrict with increased light.

Difference in size of the pupils. Anisocoria is a condition in which there is a noticeable difference in the size of the pupils. Normally, both pupils are round and equal in size. It is normal for the pupils to constrict when light increases and dilate when light decreases. The diameter of a normal pupil is between 3 and 5 mm. p. 963

The nurse is teaching a patient who is scheduled for an ultrasonography of the eye. Which statement by the patient indicates a need for further instruction? "I will be awake during this test." "I won't hear the high-frequency sound waves." "I'll have to wear a bandage over my eye after the test." "This test will help determine whether my retina is detached."

"I'll have to wear a bandage over my eye after the test." No special follow-up care is needed after an ultrasonography of the eye, so the patient does not have to wear a bandage after the test. However, the patient should be reminded not to rub or touch the eye until the effects of the anesthetic drops have worn off. The test is noninvasive and painless, and the patient remains awake during the test. The high-frequency sound waves that are bounced through the eye cannot be heard. Ultrasonography aids in the diagnosis of trauma, intraorbital tumor, proptosis, and choroidal or retinal detachment. p. 965

A patient has been prescribed eyeglasses with biconcave lenses to correct the patient's vision. What does the nurse tell the patient about the need for this correction? "The vision beyond 20 feet is normal, but near vision is poor." "The eye is unable to refract enough light and the images fall behind the retina." "The eye overbends the light and the images converge in front of the retina." "There is a refractive error caused by unevenly curved surfaces on the cornea."

"The eye overbends the light and the images converge in front of the retina." The patient has been diagnosed with myopia, or nearsightedness, meaning the patient's near vision is normal, but distance vision is poor. In this disorder, the eye overbends the light and the images converge in front of the retina. This is corrected by the use of biconcave lenses. The patient with hyperopia is unable to refract enough light and the images fall behind the retina; vision beyond 20 feet is normal, but near vision is poor in this patient. This is corrected by the use of convex lenses. Astigmatism is a refractive error caused by unevenly curved corneal surface; these uneven surfaces distort the vision. p. 960

The nurse is caring for a patient who will undergo a fluorescein angiography to get a detailed image of retinal circulation. What does the nurse tell the patient about this test? "The patient will have to sign an informed consent form." "The patient will receive 10 mL of a 5% solution of fluorescein by IV." "Mydriatic eyedrops will be instilled in the eye half an hour before the test." "Retinal and choroidal blood vessels are photographed after the dye passes through them."

"The patient will have to sign an informed consent form." The patient must sign an informed consent form before a fluorescein angiography. The patient is administered 5 mL of 10% solution of fluorescein by IV. Mydriatic eyedrops will be instilled in the eye 1 hour before the test to dilate the pupils. Retinal and choroidal blood vessels are photographed in rapid succession as the dye passes through them. This provides a detailed image of eye circulation. p. 966

Which eye procedure requires informed consent from the patient? Snellen test Ophthalmoscopy Eyedrop instillation Fluorescein angiography

Fluorescein angiography Fluorescein angiography is an invasive test and requires informed consent from the patient. Eyedrop instillation, ophthalmoscopy, and the Snellen test are not invasive procedures and do not require informed consent from the patient. p. 966

The nurse is preparing a patient for an ultrasound examination of the eye. The patient was prescribed anesthetic eye drops before the test. Which action should the nurse take when administering the eye drops? Have the patient stand up. Ask the patient to tilt the head forward. Clean the tip of the eye drop bottle with a cotton swab. Gently press and hold the corner of the eye nearest the nose.

Gently press and hold the corner of the eye nearest the nose. When administering eye drops, the nurse gently presses and holds the corner of the eye nearest the nose to decrease systemic absorption of the medication. When administering eye drops, the nurse has the patient sit in a chair and stands behind the patient. The nurse asks the patient to tilt the head backward. The tip of the eyedropper is sterile. Wiping it with a cotton swab can cause contamination and increase the risk of patient infection. p. 962

Which explanation best describes emmetropia? Near vision is poor. Distance vision is poor. Inverted images fall on the retina. Images converge behind the retina.

Inverted images fall on the retina. Emmetropia is the perfect refraction of the eye. Inverted and reversed images fall on the retina. Myopia, or nearsightedness, occurs when the eye overbends the light and the images converge in front of the retina. A patient with myopia has near vision, but poor distance vision. Hyperopia occurs when images converge behind the retina. Vision beyond 20 feet is normal, but near vision is poor. p. 960

Which equipment does the nurse use to test the color vision of a patient? Slit-lamp Jaeger card Snellen chart Ishihara chart

Ishihara chart An Ishihara chart is used to test color vision. The chart shows numbers composed of dots of one color within a circle of dots of a different color. The slit-lamp is used to examine abnormalities in the cornea, lens, or anterior vitreous humor. The Jaeger card or chart is used to measure near visual acuity. The chart has print samples of different sizes that are used to determine one's near vision. A Snellen chart or an eye-chart is used to test for distance vision—the chart has letters, numbers, pictures, or a single letter in various positions. p. 964

The nurse providing education on eye protection suggests the special need for protective eyewear for which patients? Select all that apply. Lifeguard Cab driver College student Registered nurse Racquetball player

Lifeguard Racquetball player Lifeguards are in need of eye protection from ultraviolet (UV)-A and UV-B rays because of exposure to the sun. People who play racquetball need to wear protective eyewear to prevent possible eye injury. Cab drivers may require eyewear for corrective purposes, but are not at high risk and in need of protective eyewear. College students are generally not at high risk. Although an RN would need eye protection at times, RNs do not routinely require protective eyewear for general work. p. 961

What is the main cause of cataract formation? Collapse of the eyeball Loss of transparency of the lens Necrosis and death of photoreceptors Compression of nerve fibers in the eye

Loss of transparency of the lens A cataract is a lens that has lost its transparency. The lens is normally transparent and bends the rays of light entering through the pupil so that they focus properly on the retina. High intraocular pressure (IOP) compresses the capillaries and nerve fibers in the eye which causes hypoxia in the photoreceptors and nerve fibers. Prolonged hypoxia results in photoreceptor necrosis and death and permanent nerve fiber damage. If the IOC is too low, the eyeball becomes soft and collapses, which can prevent light from reaching the light-sensitive photoreceptors in the back of the eye on the retina. p. 958

The nurse examines the vision of an older adult patient with ectropion. What is the nurse's probable assessment? Protrusion of the eye Sunken appearance of the eye Eyelashes point away and outward from the eye Lower eyelid relaxes and falls away from the eye

Lower eyelid relaxes and falls away from the eye Ectropion is a structural change of the eye caused by aging in which the lower eyelid relaxes and falls away from the eye, leading to dry-eye symptoms. Exophthalmos, or proptosis, is protrusion of the eye. Enophthalmos is the sunken appearance of the eye. Eyelashes point away and outward from the eye in normal assessment. p. 961

While reading a patient's optical chart, the nurse notices that the patient has emmetropia. Which corrective equipment does the nurse expect to see this patient wearing? Contact lenses Reading glasses Bilateral eye patches Nothing; this is normal

Nothing; this is normal Emmetropia is perfect refraction (bending of light rays from the outside world into the eye) of the eye. Emmetropia is a normal (and ideal) condition that does not require any treatment. Bilateral eye patches inhibit the patient's vision. Contact lenses are used to correct underrefraction of the eye. Reading glasses are used to correct overrefraction of the eye. p. 960

The nurse is evaluating the pupils of a patient for reaction speed. What does the nurse document if the response is sluggish? Pupil does not constrict. Pupil constricts immediately. Pupil constricts within 1 second. Pupil constricts after 1.5 seconds.

Pupil constricts after 1.5 seconds. A normal pupil should immediately constrict when a light is directed at it. The pupil response is said to be sluggish if it takes more than 1 second to constrict. Pupil response is brisk if it constricts immediately or within a second. When pupils do not constrict, it is documented as nonreactive or fixed. p. 963

The nurse educator is teaching a group of nursing students about the functions of the ocular muscles. The educator asks the group, "Which type of muscle contracts and pulls the eye downward?" Which response is correct? Inferior rectus muscle Inferior oblique muscle Superior rectus muscle Superior oblique muscle

Superior oblique muscle Contraction of the superior oblique musclepulls the eye downward. Contraction of the inferior rectus muscles and the lateral rectus muscle moves the eye diagonally down, toward the side of the head. Contraction of the inferior oblique muscle alone pulls the eye upward. When the superior rectus muscle is contracted along with the lateral rectus muscle, the eye moves diagonally upward toward the side of the head. p. 960

The nurse performing an ophthalmoscopy for a patient notes an absent red reflex. What does this indicate? The cornea is thicker than normal. The surface of the cornea is uneven. The lens is opaque or the vitreous is cloudy. There are fat deposits within the outer edge of the cornea.

The lens is opaque or the vitreous is cloudy. The absence of a red reflex during an ophthalmoscopy indicates the presence of an opaque lens or a cloudy vitreous. Astigmatism is a refractive error caused by unevenly curved surfaces of the cornea. Thickness of the cornea affects intraocular pressure reading, not refractivity. Arcus senilis is a condition caused by aging where fat is deposited within the outer edge of the cornea. p. 966

During the eye assessment of an African-American patient, what does the nurse document as an abnormal finding? Upper eyelid covers a small portion of the iris. The sclera appears yellow with pigmented dots. The cornea is transparent, smooth, shiny, and bright. The lower eyelid is relaxed and falls away from the eye.

The lower eyelid is relaxed and falls away from the eye. Ectropion, or relaxation of the lower eyelid leading to dry-eye symptoms, is an abnormal finding. When the eyes are open, the edge of the lower eyelid is below the line between the cornea and the sclera. The upper eyelid normally covers a small portion of the iris, and the eyelids should touch each other and close completely. In dark-skinned people, it is normal to find that the sclera appears yellow with pigmented dots. It is also normal for the cornea to be transparent, smooth, shiny, and bright. p. 961

What visual physiological change can happen as a result of uncontrolled hypertension? The lens loses its transparency. The eye does not refract enough light. The patient is at risk for loss of vision. The lens loses its ability to transmit light.

The patient is at risk for loss of vision. A patient with uncontrolled hypertension is at high risk for developing vision loss. A cataract is a lens that has lost its transparency. Farsightedness, or hypermetropia, occurs when the eye does not refract enough light. The lens loses its ability to transmit light as a person ages. Cataracts, farsightedness, and other lens changes are typically caused by aging or other factors unrelated to uncontrolled hypertension. p. 962

Which statements best explain the functions of the cones in the eye? Select all that apply. They provide color vision. They work at low light levels. They provide peripheral vision. They are sensory photoreceptors. They transmit impulses to the optic nerve.

They provide color vision. They are sensory photoreceptors. They transmit impulses to the optic nerve. The cones provide color and central vision. They are the sensory photoreceptors in the retina of the eye and are active at bright light levels. These photoreceptors begin the transmission of impulses to the optic nerve. The rods are the sensory photoreceptors that are active at low light levels and provide peripheral vision. p. 958

A patient is scheduled for an electroretinography. What is the purpose of this assessment? To screen the peripheral visual field To assess thickness and contours of the optic nerve To detect blood vessel changes from drugs or disease To assess retina changes due to high intraocular pressure (IOP)

To detect blood vessel changes from drugs or disease Electroretinography is an assessment to detect blood vessel changes from drugs or disease. It involves the process of graphing the retina's response to light stimulation. Perimetry is used to screen the visual fields; it draws a map of the patient's peripheral vision and any deficits. Laser imaging of the retina creates a three-dimensional view of the back of the eye. It is commonly used to assess changes in the retina due to high IOP. It also assesses the thickness and contours of the optic nerve. p. 967

Which statement regarding tonometry is correct? The tonometer applies pressure to the inside of the eye. Tonometry measures intraocular pressure using a tonometer. A person with a thicker cornea will have low tonometer reading. Readings are more accurate in the morning because intraocular pressure (IOP) is lower.

Tonometry measures intraocular pressure using a tonometer. Intraocular pressure is measured with a tonometer which applies pressure to the outside of the eye until it equals the pressure inside the eye as indicated when the cornea begins to indent. IOP is higher in the morning but may peak at any time during the day; therefore, the time of IOP measurement is always documented. The thickness of the cornea affects how much pressure must be applied before the cornea begins to indent, so a patient with a thicker cornea will record an increased tonometry reading indicating an increased IOP. Similarly, a patient with a thinner-than-normal cornea will record a lower tonometry reading even when a higher IOP is present. p. 965

The nurse is assisting a patient scheduled for a gonioscopy test. What does this test determine? Presence of infection Trauma to the cornea Type of glaucoma present Presence of refractive errors

Type of glaucoma present Gonioscopy is performed for a patient with high intraocular pressure (IOP) to determine whether open-angle or closed-angle glaucoma is present. A swab is taken from any ulcerated or inflamed area of the eye for a culture assessment to determine the presence of infection. Refractive errors are corrected by the appropriate use of eyeglasses. Trauma to the cornea is identified by a corneal staining assessment. p. 967

The eyelids are able to open and close by the work of which cranial nerve (CN)? II V III VII

VII (Facial) The facial nerve CN VII innervates the lacrimal glands and muscles controlling lid closure. CN V stimulates the blink reflex when the cornea is touched. CN II is the optic nerve (the nerve of sight) connecting the optic disc to the brain. CN III, the oculomotor nerve, innervates the muscles around the eye. p. 959