This case report describes a 26-year-old woman who experienced a spasm of the near reflex (accommodation, convergence, and miosis) when either eye was occluded or subjected to dioptric or non-dioptric blur. Her visual acuity decreased dramatically and an esodeviation was observed when either eye was occluded. Various occluders and lenses were able to trigger the spasm when a specific threshold of visual disruption was reached for each stimulus. Cycloplegia did not eliminate the spasm. This appears to be a rare case of a functional spasm of the near reflex triggered by binocular vision disruption, suggesting a potential anomaly in the neurological pathways involved in the

1. CASE REPORT
Spasm of the Near Reflex Triggered by
Disruption of Normal Binocular Vision
CAROLINE FAUCHER, OD, MSc and DANIELLE DE GUISE, OD, MSc
École d’optométrie, Université de Montréal, Montréal, Canada
ABSTRACT: A 26-year-old healthy female was referred by her optometrist to the binocular vision clinic of our institution
for the investigation of an accommodative spasm occurring during monocular conditions. Corrected binocular visual acuity
was 20/20 (6/6), with normal pupils and good ocular alignment. When the fellow eye was covered, visual acuity was
<20/200 (6/60) in each eye, miosis was present in both eyes, and the occluded eye was in esodeviation, indicating a spasm
of the near reflex. The spasm disappeared when a translucent occluder was used instead of an opaque black occluder.
Further investigation permitted us to establish that dioptric and nondioptric blur, as well as reduced light transmission, also
triggered the spasm of the near reflex, but only for specific power, opacity, or density. Cycloplegia did not eliminate the
spasm. Comparisons are made with the single other similar case found in the literature. Assumptions are made as to the
possible causes of that intermittent spasm. (Optom Vis Sci 2004;81:178–181)
Key Words: spasm of the near reflex, accommodation, convergence, miosis, uncrossed diplopia, esodeviation,
binocular vision disruption, pseudomyopia
N
ear fixation is normally accompanied by convergence,
accommodation, and miosis. When an object is brought
close to the eyes, convergence occurs to keep its image on
the foveas, the pupils constrict to increase the depth of field, and
accommodation maintains the image in focus on the retinas. The
afferent signals for this reflex follow the visual pathways to the
occipital cortex, the frontal eye fields, the Edinger-Westphal nu-
cleus, and the oculomotor nucleus in the midbrain. In the efferent
pathways, the medial rectus muscles are innervated by the oculo-
motor nerves, whereas the ciliary muscles and iris sphincters are
innervated by the parasympathetic nerves.1
This normal synkinesis
is called the near reflex,2
the near response triad,3
the accommo-
dation-convergence reaction,1, 2
or the near-point reaction.1
A spasm of the near reflex occurs when one or more of those
three components exceeds the demand required by the stimulus of
interest. When present, a spasm of the near reflex seems to vary in
time and amplitude and between individuals.4–6
Many clinical
variations are possible. Some patients may present with an accom-
modative spasm that does not involve the convergence and the
pupils, whereas others show an excessive convergence without ab-
normal accommodation.4–7
Patients presenting with a spasm of the near reflex may report
various symptoms such as blurry vision, fluctuation of vision,
headaches, ocular pain, diplopia, micropsia, or macropsia.5–7
A
spasm of the near reflex is often related to emotional factors or
psychological disorders, particularly when present in young fe-
males.5–7
It may also be related to uncorrected hyperopia in asso-
ciation with difficulties in relaxing accommodation.4, 6
Patients
with intermittent exotropia at distance trying to compensate their
deviation through accommodative convergence may also experi-
ence a spasm of the near reflex.4, 6
Finally, some organic factors
such as head trauma,8–10
diabetes, myasthenia gravis, meningitis,6
pituitary tumor,9
photosensitive epilepsy,11
and ocular or systemic
drugs6, 7
have also been investigated.
CASE REPORT
A 26-year-old female was referred in August 2002 by her op-
tometrist to the binocular vision clinic of our institution for an
accommodative spasm occurring during monocular occlusion.
The patient reported blurry vision when covering either the left or
the right eye. She had no headaches or other asthenopic symptoms.
The condition had been present since 1993 without affecting the
patient in her daily activities. The anomaly was discovered during
a routine eye examination when her myopia appeared to have
increased dramatically. A spasm of accommodation was diagnosed
at that time by an ophthalmologist who did not offer any therapy
or further investigation. The patient reported good physical and
mental health and had no history of surgery, trauma, strabismus, or
past eye injury requiring eye patching. The results of this first
evaluation as well as the follow-up visit scheduled in November
2002 were similar and are presented in the following sections.
1040-5488/04/8103-0178/0 VOL. 81, NO. 3, PP. 178–181
OPTOMETRY AND VISION SCIENCE
Copyright © 2004 American Academy of Optometry
Optometry and Vision Science, Vol. 81, No. 3, March 2004

2. The prescription glasses worn by the patient were OD Ϫ3.75
Ϫ0.50 ϫ 51 and OS Ϫ2.75 Ϫ0.50 ϫ 163. This gave a visual
acuity of OD 20/267 (1.8/24) and OS 20/380 (2/38) as measured
with a Bailey-Lovie chart while the fellow eye was covered with an
opaque black occluder. An observation of the covered eye while the
occluder was held obliquely in front of that eye revealed a pro-
nounced esodeviation. This was the case with either eye when
occluded. Binocular miosis was observed when either the left or the
right eye was occluded. As soon as the occluder was removed, the
pupils regained their normal size, and the esodeviation disap-
peared. An alternating prism cover test indicated that the deviation
was 35 prism diopter base-out at distance and 45 prism diopter
base-out at near. During binocular conditions, the ocular motili-
ties (versions) and the nearpoint of convergence were within nor-
mal limits. The stereopsis was 25 s of arc with the Randot stereo
test at 40 cm. The pupils were equal and reactive to light, with no
afferent pupillary defect.
Autorefraction performed without cycloplegia gave results that
were similar to the patient’s ophthalmic correction in both eyes
when measured without occlusion. However, a sudden increase in
myopia appeared in the tested eye as soon as an opaque occluder
was placed over the nontested eye (OD Ϫ11.75 Ϫ1.00 ϫ 55; OS
Ϫ10.25 Ϫ1.37 ϫ 167). The refraction was back to normal when
the occluder was removed. Fig. 1 shows the autorefractor screen
while taking the refraction of the right eye while the left eye was
covered (Fig. 1B) or uncovered (Fig. 1A). The miosis and the high
degree of myopia seen in Fig. 1B vs. Fig. 1A confirm the spasm of
the near reflex during occlusion of the fellow eye.
Translucent Occluder
A translucent, frosted occluder was used to measure the monoc-
ular visual acuity. At her first visit to our clinic, the patient had
20/20 (6/6) visual acuity in each eye with her ophthalmic correc-
tion, with no pupillary constriction or ocular deviation (Fig. 2A). A
cover test performed with the translucent occluder showed or-
thophoria at distance and at near. At her second visit, however, the
same translucent occluder triggered the spasm of the near reflex
even though the target and the room illumination were similar
(Fig. 2B). The results obtained between the two visits suggest that
the degree of visual disturbance needed to trigger this particular
spasm of the near reflex may vary.
Some other occluders were used: Bangerter occlusion foil bar
(Ryser filters), various convex lenses powers, neutral-density filter
bar, and Bagolini red filter bar (Sbisa bar).
Bangerter Occlusion Foil Bar (Ryser Filters)
While the patient was wearing her glasses, a Bangerter occlusion
foil bar was placed in front of either eye and moved slowly from the
most transparent to the most opaque occluder. No change in the
eyes was observed until filter 0.4, corresponding to a degradation
of the visual acuity of 20/50 (6/15), was positioned in front of the
eye. For this filter and all the subsequent more opaque filters, a
spasm of the near reflex was present.
Convex Lenses
Dioptric blur was induced monocularly by placing convex lenses
in front of one eye, over the glasses. No spasm occurred with
ϩ1.00, ϩ2.25, or ϩ3.00 D lenses (Fig. 3A). However, lenses of
ϩ3.50 D (Fig. 3B) or stronger over either the right or the left eye
FIGURE 1.
Autorefraction results for the right eye taken while (A) both eyes were
opened and (B) the left eye was covered. Note the myopic shift and miosis
in (B) confirming a spasm of the near reflex of about 8 D.
FIGURE 2.
Pictures taken at (A) the first and (B) the second visits. The frosted occlu-
sion (A) does not trigger the spasm of the near reflex at the first visit,
whereas (B) it does at the second visit. Note the miosis, esodeviation, and
temporally displaced left corneal reflex in (B).
Spasm of the Near Reflex—Faucher & de Guise 179
Optometry and Vision Science, Vol. 81, No. 3, March 2004

3. triggered the spasm of the near reflex. This test was repeated several
times, and the same result was obtained each time.
Neutral-Density Filter Bar and Bagolini Red Filter
Bar (Sbisa Bar)
A neutral-density filter bar from 0.3 to 1.8 log unit optical
density values was placed in front of one eye over the glasses. The
spasm of the near reflex was induced when filter 0.9 (5.40 log of
luminance12
) and all darker filters were placed in front of the eye.
Filter number 10 (5.00 log of luminance12
) of the Bagolini red
filter bar induced the characteristic spasm, but not the lighter ones.
A normal sensory fusion response was reported with filter 9 (5.08
log of luminance12
), whereas filter 10 induced marked uncrossed
diplopia. Those neutral-density and red filters reduce the overall
luminance with only minimal visual acuity reduction (20/20 [6/6]
to 20/25 [6/7.5]).
For all the tested conditions, a spasm of the near reflex was
triggered whenever the left or the right eye was occluded. The
spasm was always immediately reversed when any of the occluders
inducing the spasm was removed. Cycloplegia (1 drop of cyclopen-
tolate HCl 1%) did not abolish this particular reaction to occlu-
sion. Fig. 3 shows the patient with ϩ3.00 D (Fig. 3 A and C) and
ϩ3.50 D (Fig. 3 B and D) trial lenses, before cycloplegia (Fig. 3 A
and B) and during cycloplegia (Fig. 3 C and D). Note the bilateral
miosis (Fig. 3B) and esodeviation of the “covered” eye with ϩ3.50
D (Fig. 3 B and D) but not with ϩ3.00 D (Fig. 3 A and C), even
though the ϩ3.00 D lens decreases the visual acuity to about
20/200 (6/60). The cycloplegic refraction gave results similar to
the patient’s current ophthalmic correction.
Dilated slit lamp and fundus examinations were normal in both
eyes. A neurological evaluation was not recommended because the
condition was already present 10 years ago, the patient was asymp-
tomatic, and the spasm was only triggered by specific viewing
conditions.
DISCUSSION
We reported the special case of a 26-year-old woman presenting
with an occlusion-induced spasm of the near reflex. To our knowl-
edge, only one similar case has been reported in the literature.
Rutstein and Marsh-Tootle4
presented the results from the clinical
evaluation of a 27-year-old female with an accommodative spasm
induced by the occlusion of her right eye only. Their clinical find-
ings, however, differ from ours in several ways. The spasm they
reported was not accompanied by an esodeviation, and the pupils
appeared to constrict only minimally. In their report, the dioptric
blur created by a ϩ5.00 D lens did not induce the spasm of the
near reflex. They did not investigate other forms of occlusion to
elicit the spasm reported. Furthermore, cycloplegia abolished the
accommodative spasm found in their patient, whereas in the
present case, marked convergence occurred even during cyclople-
gia. The differences observed between the two cases reported may
be explained by the fact that the one reported by Rutstein and
Marsh-Tootle showed only an accommodative spasm without any
associated excess of convergence. The authors speculated that the
phenomenon could be similar to latent nystagmus in that it occurs
only when one eye is covered. They mentioned that this could also be
related to the work of their patient as a photographer, suggesting a
possiblelinkwithinstrumentmyopia.Thislatterexplanationmaynot
be applicable to our patient because she does not need to close either
eyeforherworkorhobbiesandsheneverusesamicroscope,telescope,
or any other device requiring monocular vision.
This unusual case of binocular spasm of the near reflex during
monocular occlusion without any associated history of ocular or
systemic disease or trauma is difficult to explain. The various stim-
uli used in our evaluation to disrupt the binocular vision through
different degrees and mechanisms were able to induce a spasm of
the near reflex: total occlusion, dioptric and nondioptric blur with
visual acuity disturbance, and luminance attenuation without sig-
nificant visual acuity reduction. It is interesting to note that it was
possible to determine a threshold at which each of those conflicting
stimuli disturbed the binocular vision, even though these thresh-
olds could vary between visits. The spasm was triggered whenever
the left or the right eye received a threshold signal of sufficient
attenuation. When both eyes were opened and nothing interfered
with binocular vision, the eyes remained straight, the pupils were
normal, and the patient had no symptoms. This led us to conclude
FIGURE 3.
Dioptric blur with a ϩ3.00 D lens (A) does not induce the spasm, whereas
(B) it does with a ϩ3.50 D lens. The spasm is also triggered during
cycloplegia (D) with the ϩ3.50 D lens but (C) not with the ϩ3.00 D lens.
180 Spasm of the Near Reflex—Faucher & de Guise
Optometry and Vision Science, Vol. 81, No. 3, March 2004

4. that this was a functional rather than pathological process. We can
speculate, however, that an anomaly might be present somewhere
in the neurological pathways of the nearpoint reaction, likely in the
midbrain, because both sides were affected equally and all compo-
nents of the near triad were involved. Furthermore, recent findings
suggest that the human parietal cortex-rostral superior colliculus
system plays a role in the control of accommodation and vergence
eye movements.13
In conclusion, an interesting intermittent spasm of the near
reflex triggered by binocular vision disturbance was presented. An
exhaustive search of the literature revealed that this is a very un-
usual case. Comparison with a previous case report showed that
different clinical presentations are possible. Even though this case
could not be elucidated, the existence of the phenomenon led us to
believe that a neurological particularity may exist. This case ap-
pears to be benign. It is, however, important to thoroughly inves-
tigate any patient presenting with a spasm of the near reflex to rule
out any pathological process. From a clinical point of view, this
unusual case demonstrates the utility of various types of occluders
for evaluating binocular visual function in specific patients. Fi-
nally, it stresses the importance of attentively observing the patient
during visual acuity testing. As we always remind our optometry
students: keep looking at the eyes, not the chart, because you never
know what the eyes may reveal!
ACKNOWLEDGMENTS
We thank Doctor Hélène Kergoat, OD, PhD, for reviewing the manuscript
and for her helpful advice and Mr. Denis Latendresse for his computer graphics
expertise.
Submitted March 3, 2003; accepted November 15, 2003.
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Caroline Faucher
École d’optométrie, Université de Montréal
C.P. 6128 succursale Centre-Ville
Montréal, Québec H3C 3J7, Canada
e-mail: caroline.faucher@umontreal.ca
Spasm of the Near Reflex—Faucher & de Guise 181
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