Page 1930 - Saunders Comprehensive Review For NCLEX-RN

refractive errors.
b. Myopia (nearsightedness): Refractive
ability of the eye is too strong for the
eye length; images are bent and fall in
front of, not on, the retina.
c. Hyperopia (farsightedness): Refractive
ability of the eye is too weak; images
are focused behind the retina.
d. Presbyopia: Loss of lens elasticity
because of aging; less able to focus the
eye for close work and images fall
behind the retina.
e. Astigmatism: Occurs because of the
irregular curvature of the cornea;
image focuses at 2 different points on
the retina.
2. Assessment
a. Refractive errors are diagnosed through
a process called refraction.
b. The client views an eye chart while
various lenses of different strengths
are systematically placed in front of the
eye and is asked whether the lenses
sharpen or worsen the vision.
3. Nonsurgical interventions: Eyeglasses or contact
lenses
4. Surgical interventions
a. Radial keratotomy: Incisions are made
through the peripheral cornea to
flatten the cornea, which allows the
image to be focused closer to the
retina; used to treat myopia.
b. Photorefractive keratotomy: A laser
beam is used to remove small portions
of the corneal surface to reshape the
cornea to focus an image properly on
the retina; used to treat myopia and
astigmatism.
c. Laser-assisted in-situ keratomileusis
(LASIK): The superficial layers of the
cornea are lifted as a flap, a laser
reshapes the deeper corneal layers, and
then the corneal flap is replaced; used
to treat hyperopia, myopia, and
astigmatism.
d. Corneal ring: The shape of the cornea is
changed by placing a flexible ring in
the outer edges of the cornea; used to

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