committees prohibit mixing of medication, so a noncommercial
mix of agents (or a spray) is not used in most academic practices.
Some pediatric ophthalmologists will instill one drop of topical
proparacaine before cyclopentolate to decrease the stinging (and
possibly enhance absorption). I do not, as proparacaine also stings,
and the combination means that the child needs 4 drops rather
than 2. Similar hospital policy issues exist with a combination of
topical anesthesia and cycloplegic as described above. Tropicamide
alone can produce cycloplegia, but its half-life is so short as to make
it not useful in a busy pediatric office. Atropine can be used for
difficult refraction but in my experience is almost never necessary.
In addition to being more difficult to examine, children also
have different visual demands than adults. The working distance of
most preverbal children is very different from that of adults. Gen-
erally, children have minimal or no need for sharply focused dis-
tance acuity (although we invariably describe visual function on
the basis of distance acuity). This is especially true for children of
the age of 3. The preschool child typically has a working distance of
1 to 2 m. Thus, in contrast to older children and adults, preschool
children have minimal need for mild symmetric myopia correction.
Children also have different accommodative abilities than
adults. There is vast literature, dating back to the early 1900s, that
describes the extremely high levels of accommodation that young
Healthy children in their first decade of life
typically possess 12 D or more of accommodative function.3
cordingly, even moderate uncorrected hypermetropia does not de-
grade acuity in young children.4
As a result, there is minimal need
to correct moderate hyperopia, except when it is associated with
The final unique characteristic of a child’s visual system is its
increased risk of amblyopia, from anisometropic, strabismic, or
high spherical or cylindrical refractive errors. In contrast to aniso-
metropia or strabismic adults who do not jeopardize their visual
systems by failing to correct the nondominant eye, the young child
is at risk of permanent vision loss unless the eyes are straight and
have symmetrical and adequately focused retinal images. However,
the level of refractive error that produces amblyopia for each par-
ticular child is different, and depends on other factors, such as the
Thus, no firm evidence-based recommendations can
be made regarding the threshold levels of refractive error that need to
be corrected to protect against the development of amblyopia.
The above characteristics of children mean that spectacle pre-
scribing for children is an art, requiring interpretation of the child’s
refractive error and visual acuity within the global evaluation of the
child. This is especially true for children who are not yet able to
provide an accurate objective visual acuity measurement, and for
whom the only information available is the cycloplegic refractive
error, and the visual behavior of the child. The remainder of this
manuscript will detail the thought processes many pediatric oph-
thalmologists use to determine when to prescribe spectacles.
Prescribing for Myopia
Because of the minimal risk of amblyopia with symmetrical
myopia, prescribing for symmetric myopia should solely be based
upon anticipated visual acuity needs. Two fundamental observa-
tions underscore the minimal need to prescribe spectacles for sym-
metric low levels of myopia in young children. First the visual
acuity demands of very young children are unlikely to exceed
20/40 before the late elementary school years. Although the fovea
is adequately developed and capable of 20/20 acuity by 6 years of
age, most of the items a child views are not small enough to require
such fine resolution. The second factor impacting prescribing for
myopia in children is their proximity to the visual target. Unlike
adolescents and adults, who are required to view distant targets
with high resolution, most children have a working distance that is
close to them. Infants, for example, have a very proximate working
distance; a newborn infant typically only needs to see her mother’s
face, which often is only 25 cm away. The ocular structures of
infant eyes are also not capable of high spatial resolution. Hence,
only extreme myopia (approximately minus 4 D or more) is prob-
ably necessary to treat in this age group. Late in the first year of life,
the eyes become anatomically capable of better spatial resolution,
but until a child begins to walk, he is rarely interested in objects
more than 2 to 3 feet away. Therefore, Ϫ3.00 D of myopia is a
threshold one may consider correcting in the very young child.5
Guidelines from the American Academy of Ophthalmology’s Pre-
ferred Practice Pattern6
and the Pediatric Eye Disease Investigator
both set 3.00 D of myopia as a threshold for correction. A
similar magnitude was established as a criterion to detect using pre-
school vision screening by the Vision Screening Committee of the
American Association of Pediatric Ophthalmology and Strabismus.7
Children in kindergarten or first grade typically do not use a
chalkboard at school, but do most things at school at a desk, and
are beginning to read. Thus, arguably even up to 1.5 D of myopia
may not be important to correct for children in this age group.
However, older children, beginning in the mid elementary school
years, when acuity can be tested accurately, warrant full correction
of myopia. The optometry community probably has less tolerance
for undercorrection of myopia in preschool children than does the
pediatric ophthalmology community. Reasons for this are unclear.
However, there is no well-documented evidence that either under-
or overcorrection of myopia stimulates or retards its progression.
In fact, a recent well-controlled study failed to find any effect, even
when myopia was overcorrected.8
Most pediatric ophthalmologists do not prescribe bifocals in
young myopic children to retard myopia progression despite the
COMET conclusions. This is because most feel that a small difference
in myopia as an adult is of little clinical relevance compared with the
added cost and cosmetic issues associated with bifocal wear. Similar
thought processes limit the use of atropine and pirenzipine.
Correction of Astigmatism
Mild to moderate meridional astigmatism of Ͻ1.5 D produces
minimal degradation of visual acuity in the young child and is not
felt to be amblyogenic when symmetric.5
degrades visual acuity more, and may be amblyogenic with slightly
less magnitude. High levels of astigmatism are typically found in
the American Indian population and therefore should be screened
If astigmatism is balanced by spherical refractive error (com-
pound myopic astigmatism or compound hyperopic astigmatism),
the spherical equivalent places the Conoid of Sturm nicely on the
retina. Also, depending upon the degree of accommodation used,
the necessary portion of the visual environment may be sufficiently
focused to prevent amblyopia or significantly decreased acuity.
Spectacles for Children: A Pediatric Ophthalmologist’s Approach—Donahue 111
Optometry and Vision Science, Vol. 84, No. 2, February 2007
This may explain why some patients tolerate moderate levels of
astigmatism without spectacles.
Preverbal children with symmetric astigmatism Ͻ1.5 D typi-
cally do not need correction unless the astigmatism is associated
with high myopia or high hyperopia. The AAPOS vision screening
committee has set a threshold of 1.5 D of meridional cylinder as a
target condition to detect with preschool vision screening.7
Vision in Preschoolers (VIP) study group had a similar threshold10
as does the Pediatric Eye Disease Investigator Group.5
atric Preferred Practice Pattern for Children aged 2 to 3 years
suggests prescribing at a slightly higher magnitude (2.0 D).6
elementary school-age children with 1.0 to 1.5 D of astigmatism
may benefit from correction, and a trial of spectacles is probably
warranted for such children. However, the parents should be in-
formed that not wearing spectacles will not harm a child’s vision,
and if children choose not to wear the glasses, they should not force
them to do so. For children in the late elementary school years, a
postcycloplegic manifest refraction to compare best corrected vi-
sual acuity with uncorrected acuity can help guide the decision of
whether or not to prescribe spectacles for lower levels of astigma-
tism. In all such situations, one would prescribe the full cylinder
that can be tolerated.
Correction of Anisometropia
Anisometropia can be a very powerful amblyogenic factor, and
anisometropic amblyopia is extremely difficult to detect with tra-
ditional screening of preliterate children. However, the treatment
of what appears to be asymptomatic anisometropia detected either
on a routine eye examination or following referral from a photore-
fractive screening causes a dilemma for the ophthalmologist and
optometrist, because severe levels of anisometropia often cause
amblyopia but mild and moderate levels often do not.11,12
dition, some children, especially those having a family history of
amblyopia may develop amblyopia even with relatively small levels
of cylindrical or spherical ametropia. Finally, the natural history of
anisometropic refractive error over time is not well established. For
example, a child with moderate anisometropia may have the
ametropia completely resolve before school entry. Whether or not
such anisometropia needs to be treated is unclear. Anisometropia
usually produces amblyopia by the age of 3 years12
; thus, if the
uncorrected acuity is normal at that age, treatment is likely unnec-
essary. In addition, recent evidence from the amblyopia treatment
study series has demonstrated that many preschoolers with mild to
moderate anisometropic amblyopia can have restoration of good
visual acuity and stereopsis simply with spectacle correction alone,
even at late ages.13,14
Hence, the importance of detecting and
treating very small levels of anisometropia in very young children,
even when amblyopia is already present, is now open to question.
The threshold for treating anisometropia is also controversial.
The vision screening committee of AAPOS recommends that pre-
school screening detect children having Ͼ1.5 D anisometropia.7
similar threshold was chosen by the VIP study group.10
within 0.5 D of this value are suggested by the PEDIG5
American Academy of Ophthalmology Preferred Practice Pattern.6
Evidenced-based data support these thresholds. Weakley11
uated acuity results from several hundred anisometropic children
seen in his practice and concluded that Ͼ1.0 D of spherical aniso-
metropic hyperopia and Ͼ1.5 D of cylindrical hypermetropia pro-
duced an increased risk of amblyopia development. A retrospective
review by Kutschke et al.15
found that anisometropic amblyopia was
never associated with Ͻ1.5 D of anisometropia unless a coexisting
strabismus was present, and that 1.0 D appeared to be a threshold at
which anisometropia began to be associated with amblyopia.
An additional difficulty with treating anisometropic amblyopia
is that the dominant fellow eye typically has minimal refractive
error, and therefore, many children do not appreciate any improve-
ment and do not wish to wear the glasses. This is the primary
instance in pediatric ophthalmology in which spectacle compli-
ance is often difficult and needs to be forced; in most other situa-
tions, compliance with spectacles wear is not difficult, even for
young children, providing the above guidelines are adhered to (and
the prescription is correct!).
Treatment of anisometropia should consist of symmetric reduc-
tion of hypermetropia of up to 2.0 D, prescribing the full amount
of cylinder unless the child has an associated accommodative es-
otropia. In this situation, all hypermetropia should be corrected
along with the full cylindrical correction. This practice has been
well established by clinical care, and is used in the PEDIG study
Prescribing for Hypermetropia
Prescribing spectacles for hypermetropia also presents unique
challenges. Uncorrected hypermetropia can produce accommoda-
tive esotropia, strabismic amblyopia, and isoametropic (refractive)
amblyopia. Fortunately, the practitioner is aided by evidence-
based guidelines from population studies, as well as surveys.
Most young children are mildly hypermetropic; hence, moder-
ate hypermetropia does not need to be corrected.6
for treatment of hypermetropia, however, is controversial. Some
evidence is available to help guide this decision. The prevalence of
hypermetropia has been estimated in several studies.16,4,17
difficult to compare the studies, as the definition of hypermetropia
varies based upon whether the hypermetropia is thought to be
or if it is simply being distinguished from
Nevertheless, these studies generally show that
fewer than 1% of healthy children have Ͼ4 D of hyper-
; other studies not referenced here have reached simi-
A recent study examined the relationship of increasing hyper-
metropia with degradation of visual acuity, and failed to dem-
onstrate any significant reduction in acuity until hypermetropia
exceeds 4 D.4
This threshold represents only a very small por-
tion of the population.4,16
Prescribing spectacles for hypermetropia has also been postu-
lated to improve reading ability. An excellent study by Helveston
demonstrated that in the absence of acuity degradation there is no
relationship between reading ability, school performance, and level
Thus, children with moderate levels of hyper-
metropia do not need spectacles simply to improve their near vi-
sion or reading ability.
The treatment of moderate to high hypermetropia has been
demonstrated to decrease the risk of strabismus and amblyopia in
prospective randomized studies. Atkinson et al. compared treat-
ment vs. no treatment of otherwise healthy hypermetropes.20
112 Spectacles for Children: A Pediatric Ophthalmologist’s Approach—Donahue
Optometry and Vision Science, Vol. 84, No. 2, February 2007
dren with hypermetropia Ͼϩ3.50 D had a 13 times greater risk of
developing strabismus or amblyopia than did children who had no
significant hypermetropia. Prescribing spectacles for the hyper-
metropia decreased the risk substantially, but these children re-
mained at a four times greater risk than the general population.
These results suggest that levels of hypermetropia Ͼ4.00 D should
warrant consideration of correction, especially if there is a family
history of strabismus or amblyopia, or if there is a poorly controlled
phoria without correction.
Guidelines for treatment of hypermetropia have also been de-
termined from practice patterns and surveys. Most surveys have
demonstrated that optometrists have a lower threshold for prescrib-
ing spectacles for children than do ophthalmologists. Reasons for this
are unclear. Lyons et al. performed a survey of 212 optometrists and
102 ophthalmologists (both comprehensive and pediatric).21
were asked whether they would prescribe spectacles for a 6-year-old
child having between ϩ3.00 and ϩ4.00 D hypermetropia. Op-
tometrists prescribed spectacles in 33% of instances, whereas only
5% of ophthalmologists did. For 2-year-old children, most oph-
thalmologists and optometrists began to prescribe spectacles at a
level of ϩ5.00 D of hyperopia.
A separate but similar survey of Pediatric Ophthalmologists
demonstrated that threshold levels for prescribing hypermetropia
vary by child age and by the level of hyperopia.22
Fifty percent of
Pediatric Ophthalmologists would prescribe spectacles for children
younger than the age of 2 years when hyperopia reached ϩ5.00 D.
For children older than age 2 years, 50% prescribed at 4.00 D of
The American Academy of Ophthalmology has guidelines for
prescribing spectacles in their Preferred Practices Patterns (PPP).6
The PPP “Childhood Eye Examinations” indicates that “cyclople-
gia is mandatory” in determining the refractive needs of children.
For children aged 3 years and younger, they suggest prescribing at
ϩ4.50 D of hypermetropia. For children aged 4 years or older,
they indicate that spectacles should be prescribed if necessary to
improve acuity, or alleviate esotropia. No numerical threshold
guidelines are given in this situation.
A final set of guidelines are provided from papers regarding pre-
school vision screening techniques. The American Academy of Pedi-
atric Ophthalmology and Strabismus (AAPOS) Vision Screening
Committee has published standards on what should be detected with
preschool vision screening. They suggest that vision screening instru-
ments and tests should detect hypermetropia Ͼϩ3.50 D in any
Likewise, the Vision in Preschoolers study, which is pri-
marily optometry based, defines hypermetropia Ͼϩ3.50 D as a con-
dition that is important to detect.10
Concern abounds about the effect of spectacle correction of
hypermetropia on the eventual emmetropization of the eye. Stud-
ies both support and oppose this notion. The issues regarding this
complicated topic are deferred to Dr. Mutti’s paper, which is part
of this transcript.
When a decision is made to correct hypermetropia, how much
should be corrected? Full correction in the nonstrabismic child
should be avoided as the accompanying blur at distance can be a
factor that hinders compliance. The Pediatric Eye Disease Investi-
gator Group has mandated symmetric reduction of up to 1.5 D of
spherical hypermetropia when treating anisometropic amblyopia
in the amblyopia treatment studies, with full correction of all hy-
permetropia for the strabismic child.23–25
An exception to these threshold levels for prescribing for hyper-
metropia is for children with developmental delay or Down Syn-
drome. Some children, especially those with severe development
delay, are minimally interactive, and have very little need for spec-
tacle correction. Children with significant cortical visual impair-
ment, severe structural ocular abnormalities, and marked mental
retardation are examples. Many such children will not appreciate
the improvement provided by the spectacles and will not tolerate
them on their face. In my experience, well-minded parents often
become exhausted in futile attempts to keep such glasses on these
children, fearing that not wearing them will damage the child’s vision.
In contrast, children with Down syndrome are often hypo-accommo-
benefit from spectacle correction at lower thresholds.
In summary, a consensus appears to exist to prescribe spectacles
for hypermetropia in children when hypermetropia exceeds 3.5 D
and acuity cannot be adequately determined. As accurate determi-
nation of uncorrected visual acuity is often quite difficult until
approximately age 4 years, a better method considers a child’s
visual demands, based upon the child’s age, his or her baseline level
of cycloplegic refractive error, and whether there is a family history
of amblyopia or strabismus. A discussion with the parents that
reassures them that the lack of wearing spectacles will not harm the
child in the absence of anisometropia is also important. Finally,
parents should be warned that children who develop eye crossing
should be seen immediately, as such an observation mandates spec-
tacle correction of full hypermetropia.
This work was supported by Research to Prevent Blindness, New York, New
Received October 7, 2006; accepted December 6, 2006.
1. Donders FC. Accommodation and Refraction of the Eye. London:
New Sydenham Society; 1864.
2. Katz M, Kruger PB. The human eye as an optical system. In: Tasman
W, Jaeqer EA, eds. Duanes Clinical Ophthalmology. vol 1.
Philadelphia: Lippincott-Raven; 1998:chap 33.
3. Glasser A, Campbell MC. Presbyopia and the optical changes in the
human crystalline lens with age. Vision Res 1998;38:209–29.
4. Robaei D, Rose K, Ojaimi E, Kifley A, Huynh S, Mitchell P. Visual
acuity and the causes of visual loss in a population-based sample of
6-year-old Australian children. Ophthalmology 2005;112:1275–82.
5. Holmes JM, Clarke MP. Amblyopia. Lancet 2006;367:1343–51.
6. American Academy of Ophthalmology. Pediatric Eye Evaluations,
Preferred Practice Pattern. San Francisco: American Academy of
7. Donahue SP, Arnold RW, Ruben JB. Preschool vision screening:
what should we be detecting and how should we report it? Uniform
guidelines for reporting results of preschool vision screening studies.
J AAPOS 2003;7:314–16.
8. Kushner BJ. Does overcorrecting minus lens therapy for intermittent
exotropia cause myopia? Arch Ophthalmol 1999;117:638–42.
9. Harvey EM, Dobson V, Miller JM. Prevalence of high astigmatism,
Spectacles for Children: A Pediatric Ophthalmologist’s Approach—Donahue 113
Optometry and Vision Science, Vol. 84, No. 2, February 2007
eyeglass wear, and poor visual acuity among Native American grade
school children. Optom Vis Sci 2006;83:206–12.
10. Schmidt P, Maguire M, Dobson V, Quinn G, Ciner E, Cyert L, Kulp
MT, Moore B, Orel-Bixler D, Redford M, Ying GS. Comparison of
preschool vision screening tests as administered by licensed eye care
professionals in the Vision in Preschoolers Study. Ophthalmology
11. Weakley DR Jr. The association between nonstrabismic anisometro-
pia, amblyopia, and subnormal binocularity. Ophthalmology 2001;
12. Donahue SP. Relationship between anisometropia, patient age, and
the development of amblyopia. Am J Ophthalmol 2006;142:132–40.
13. Scheiman MM, Hertle RW, Beck RW, Edwards AR, Birch E, Cotter
SA, Crouch ER Jr, Cruz OA, Davitt BV, Donahue S, Holmes JM,
Lyon DW, Repka MX, Sala NA, Silbert DI, Suh DW, Tamkins SM.
Randomized trial of treatment of amblyopia in children aged 7 to 17
years. Arch Ophthalmol 2005;123:437–47.
14. Cotter SA, Edwards AR, Wallace DK, Beck RW, Arnold RW, Astle
WF, Barnhardt CN, Birch EE, Donahue SP, Everett DF, Felius J,
Holmes JM, Kraker RT, Melia M, Repka MX, Sala NA, Silbert DI,
Weise KK. Treatment of anisometropic amblyopia in children with
refractive correction. Ophthalmology 2006;113:895–903.
15. Kutschke PJ, Scott WE, Keech RV. Anisometropic amblyopia. Oph-
16. Kuo A, Sinatra RB, Donahue SP. Distribution of refractive error in
healthy infants. J Aapos 2003;7:174–7.
17. Kleinstein RN, Jones LA, Hullett S, Kwon S, Lee RJ, Friedman NE,
Manny RE, Mutti DO, Yu JA, Zadnik K. Refractive error and eth-
nicity in children. Arch Ophthalmol 2003;121:1141–7.
18. Donahue SP, Baker J. Hyperopia: how do we define abnormal? Arch
19. Helveston EM, Weber JC, Miller K, Robertson K, Hohberger G,
Estes R, Ellis FD, Pick N, Helveston BH. Visual function and aca-
demic performance. Am J Ophthalmol 1985;99:346–55.
20. Atkinson J, Braddick O, Robier B, Anker S, Ehrlich D, King J,
Watson P, Moore A. Two infant vision screening programmes: pre-
diction and prevention of strabismus and amblyopia from photo- and
videorefractive screening. Eye 1996;10(Pt 2):189–98.
21. Lyons SA, Jones LA, Walline JJ, Bartolone AG, Carlson NB, Kattouf
V, Harris M, Moore B, Mutti DO, Twelker JD. A survey of clinical
prescribing philosophies for hyperopia. Optom Vis Sci 2004;81:
22. Miller JM, Harvey EM. Spectacle prescribing recommendations of
AAPOS members. J Pediatr Ophthalmol Strabismus 1998;35:51–2.
23. Pediatric Eye Disease Investigator Group. A randomized trial of at-
ropine vs. patching for treatment of moderate amblyopia in children.
Arch Ophthalmol 2002;120:268–78.
24. Repka MX, Beck RW, Holmes JM, Birch EE, Chandler DL, Cotter
SA, Hertle RW, Kraker RT, Moke PS, Quinn GE, Scheiman MM;
Pediatric Eye Disease Investigator Group. A randomized trial of
patching regimens for treatment of moderate amblyopia in children.
Arch Ophthalmol 2003;121:603–11.
25. Holmes JM, Kraker RT, Beck RW, Birch EE, Cotter SA, Everett DF,
Hertle RW, Quinn GE, Repka MX, Scheiman MM, Wallace DK;
Pediatric Eye Disease Investigator Group. A randomized trial of pre-
scribed patching regimens for treatment of severe amblyopia in chil-
dren. Ophthalmology 2003;110:2075–87.
Sean P. Donahue
Department of Ophthalmology
1211 21st Avenue S
104 Medical Arts Building
Nashville, TN 37212-1348
114 Spectacles for Children: A Pediatric Ophthalmologist’s Approach—Donahue
Optometry and Vision Science, Vol. 84, No. 2, February 2007