H

hordeolum A bacterial INFECTIONof a gland or an
eyelash follicle along the edge of the eyelid, com-
monly known as a stye. A hordeolum causes
swelling, redness, PAIN, and a discharge that leaves a
crusty layer on the eyelids during sleep. The doctor
can usually diagnose hordeolum by its presenta-
tion. BLEPHARITIS(infection of the inside surface of
the eyelid) and CONJUNCTIVITIS(infection of the con-
junctiva, the membrane lining the eyelids) may
instigate, accompany, or follow hordeolum. The
doctor often chooses to anesthetize the area and
lance (make tiny punctures or incisions under ster-
ile conditions) the hordeolum to drain its contents
and relieve the pressure. Further treatment is oph-
thalmic ANTIBIOTIC MEDICATIONS, typically in oint-
ment form, applied to the area. Sometimes oral
antibiotic medications are also necessary. Warm,
moist compresses soothe the irritated tissues and
help draw out any remaining pus.
Most hordeola clear up in 7 to 10 days with
treatment and heal without residual conse-
quences. A hordeolum does not itself cause VISION
IMPAIRMENT, though untreated hordeola can lead to
significant EYEproblems if the infection spreads to
other structures of the eye. Some people experi-
ence recurring hordeola, while others experience
only a single episode. A hordeolum may also form
the basis for a CHALAZION (painless nodule) to
develop in its place.
See also BACTERIA; ECTROPION; ENTROPION.

hyperopia A refractive error, commonly called
farsightedness, in which the EYE has difficulty
focusing on near objects. Hyperopia results when
the focal point of lightwaves entering the eye

extends past the RETINA, causing the images the

retina registers to be blurred. The refractive error

occurs because the distance from the front to the

back of the eye is shorter than normal. Symptoms

of hyperopia include

• squinting when reading or doing close work


• HEADACHE


• fatigued eye muscles (aching around the eyes)


• blurred vision when looking at near objects yet
  clear vision when looking at distant objects

CORRECTIVE LENSES(eyeglasses or contact lenses)

can compensate for hyperopia by altering the focal

point of lightwaves so it falls directly on the retina.

They do so by refracting (bending) the lightwaves

outward. REFRACTIVE SURGERY, which permanently

alters the shape of the CORNEA, can provide refrac-

tive correction for people with mild to moderate

hyperopia. Hyperopia sometimes occurs following

refractive surgery for MYOPIA(nearsightedness) as

a consequence of overcorrection. Eye profession-

als denote refractive corrections in units of meas-

ure called diopters. For hyperopia, the expression

of diopter is a positive number. Corrective lenses

for hyperopia have a magnifying appearance that

make the eyes look bigger than they are.

Hyperopia is less common than myopia, affect-

ing about 20 to 25 percent of adults. Few people

who have hyperopia have greater than +6

diopters of refractive error, so nearly always cor-

rective measures result in normal VISUAL ACUITY.

See also ASTIGMATISM; PRESBYOPIA; REFRACTIVE

ERRORS.

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