Collewijn, "Gaze-shift dynamics in subjects with and without symptoms of convergence insufficiency
: influence of monocular preference and the effect of training," Vision Research, vol.
In terms of amount of the deviation at near and distance fixation, XT has been distinguished into four patterns (basic, convergence insufficiency
pattern, divergence excess pattern, and simulated divergence excess pattern), according to the classification proposed by Duane .
The baseline testing included Convergence Insufficiency
Symptom Survey (CISS) questionnaire , visual acuity, cover test at distance and near, accommodative amplitude and facility, Monocular Estimation Method (MEM) retinoscopy , objective assessment of lag of accommodation, near point of convergence, step vergence, vergence facility, and a cycloplegic refraction using 1% Tropicamide.
The 15-question pencil-and-paper Convergence Insufficiency
Symptoms Survey (CISS) questionnaire was completed during each data collection session by selecting the frequency of the particular near vision symptom (Figure 2).
On orthoptic examination, 27% patients had exophoria for near convergence, 50% had convergence insufficiency
or decreased convergence amplitude, and 23% had esophoria [Table 10].
A recent Romanian study revealed that roughly 3 in 5(60.4%) of young adult patients complaining of blurred vision at near work suffered from convergence insufficiency
. Similar studies conducted by Southern California college of optometry found that approximately 1 in 8 i.e.
The study by the NEI found that in-office vision therapy was the best treatment for one type of problem convergence insufficiency
This is called convergence insufficiency
, which can cause eye strain, headaches, blurred and double vision.
Prospective comparison of convergence insufficiency
and normal binocular children on CIRS symptom surveys.
There is a problem with the way eyes track that can cause dyslexia; it is called "convergence insufficiency
disorder." When I look at your eyes, I wonder if you have the problem.
According to two separate studies, there is a "high occurrence" of convergence insufficiency
(CI), a vision disorder that causes the eyes to move outward, among children with attention-deficit/hyperactivity disorder (ADHD).