Accommodation (focusing) Dysfunction is a non‐aging, non‐refractive, neuromuscular abnormality of the visual system.In simpler terms, an individual who cannot hold prolonged near focus is considered to have accommodation dysfunction.Accommodation is the adjustment of an eye to see objects at different distances by changing the shape of the lens through the action of the ciliary muscles. Any dysfunction or interference with the ability of eye to accommodate is termed as accommodative dysfunction and can be of following types:

  • Accommodative excess/spasm is excessive accommodative response than required for accurate near binocular vision
  • Accommodative infacility/inertia is slowness to change accommodation from one level to another
  • Accommodative insufficiency is the reduced level of focus stamina (accommodation) for accurate near binocular vision. Almost 80% of Convergence excess children also demonstrate Accommodative insufficiency.
  • Ill-sustained accommodation is a condition in which the AA is normal, but fatigue occurs with repeated accommodative stimulation.
  • Accommodative paresis/palsy is the absence of an ability to produce an accommodative response as a consequence of some disease or trauma.

Accommodative paresis, excess, and ill-sustained accommodation are relatively rare, and accommodative insufficiency and infacility are the two most common types of accommodative dysfunctions.

Characteristics of Accommodation Dysfunction

  • Acquired fatigue problem which produces eye strain and strain
  • Inadequate accommodative accuracy, facility and flexibility
  • Reduced amplitude of accommodation
  • Inability to easily sustain accommodation
  • Is caused by prolonged near work

Cause of Accommodation DysfunctionAccommodation dysfunction can develop because of any of the following reasons:

  • Poor general health of the person due to chronic fatigue syndrome
  • Certain medications like Ritalin, antihistamines etc.
  • High degree far-sightedness
  • Eye turn especially Esotropia
  • Extreme Near Point Stress
  • Prolonged near tasks
  • Stressful near focused task

Symptoms of Accommodative Dysfunctions:Symptoms appear when eye is under excessive near stress for prolonged period and includes the following:

  • Visual Stress symptoms:
    • Red eyes
    • Sore eyes
    • Headache
    • Blurry vision
  • Reduced near point acuity
  • Excessive rubbing of the eyes
  • Eye strain
  • Reading problems
  • Periodic blurring of distance vision after prolonged near visual activities
  • Periodic double near vision
  • Difficulty to sustain near vision
  • Glare with computer screen or even page
  • Excessive fatigue
  • Sensitivity to light
  • Poor concentration
  • Abnormal postures to make work closer to the eye e.g. tilting of head
  • It can be asymptomatic with patient or his relative complaining of avoidance of reading or other close work

Early detection and prevention of Accommodative dysfunction

Although early detection does not assure long-term sustainability of accommodative dysfunction but it is definitely ideal to get it diagnosed before the condition worsens. In fact, in the case of children, it is all the more important to diagnose it as early as possible to allow the child to grow properly and avoid any kind of effect on his future school performance. For this, the first eye examination of the child should be just after he completes 6 months age, followed by the second examination at 3 years of age if everything is fine. But in the case of any abnormality in the vision, early follow-ups should be planned and followed.

Diagnosis of Accommodation dysfunction

The evaluation of accommodative dysfunction may include, but is not limited to the following areas:

  • Complete patient history
  • Thorough eye examination including:
    • Visual Acuity
    • Refraction
    • Ocular Motility and Alignment
    • Near Point of Convergence
    • Near Fusional Vergence Amplitudes
    • Relative Accommodation Measurements
    • Accommodative Amplitude and Facility
    • Stereopsis
    • Ocular Health Assessment
  • Systemic Health Screening

Treatment strategies for Accommodative dysfunction:

  • Correction of any refractive error like far-sightedness, near-sightedness, astigmatism etc.
  • Addition of plus lenses to stimulate accommodation
  • Training Spectacle lenses for all close work to improve focusing stamina
  • Vision therapy to restore normal accommodative dysfunction includes following techniques or procedures:
    • Accommodative rock technique is done by alternating lens powers, or by alternating fixation distance. Rocking with lenses bolster the sufferer’s ability to sustain focus while reading for extended periods of time.
    • Monocular activities with the help of eye patches
    • Binocular activities with a loose plus or minus lens held in front of one eye, and a loose prism lens in front of the other eye to dissociate.
    • Volunteer accommodation controlling techniques