Vishal Biswas, M. Optom

Assistant Professor and Program Coordinator, Department of Optometry, School of Allied Health Sciences, Noida International University, India


Computer vision syndrome (CVS) is the term used for anomalies associated with eye and visual issues brought on by extended computer use. (1) It is mostly misapprehended with Computer User Complex (CUC). CUC is a condition that includes a group of symptoms relatable to visual and ergonomic abnormalities. In the medical field, categorical symptoms  resulting from a single condition are called complex (mobility disorders, etc.). (2) Therefore, the symptoms linked to computer use resemble a complex more than a syndrome in this  regard. As a result, CUC is more compatible with computer usage than CVS, since it takes ergonomic and visual anomalies into account.

Assessment of Binocularity

Most often, accommodative parameters are impacted after using a computer. (3) However, all the stepwise tests should be followed while assessing a patient with complaints followed by computer usage. When testing with minus lenses, which encourage the eye’s focusing or accommodation function, it is common to observe disruptions in this process. For example, indicators like the Binocular Accommodative Facility, which typically leans towards the minus side, and the Positive Relative Accommodation may be affected. Additionally, indirect measures like Negative Fusional Vergence tend to decrease in comparison to the established normative values. The best way to differentiate between accommodative issues such as accommodative in-sufficiency or ill-sustained accommodation is by performing the binocular vision assessment. From the assessment’s results, the inability to maintain clear vision under binocular conditions is indicative of an anomaly associated with vergence and the accommodative system. Whereas, if the blurriness fades off with both eyes open, then the problem lies with accommodation. All these abnormalities are normally seen in patients with CUC and CVS. The signs are shown in Table 1.

Table 1: Visual Signs related to Computer User Complex (CUC)

If Exophoria is present:
Reduced Near point of convergence
Phoria greater in near than distance
Lower AC/A ratio
Low Positive fusional vergence (PFV) for distance and near
Low Negative relative accommodation (NRA)
Low binocular accommodative facility (BAF) and difficulty in clearing with plus lens
Low Monocular estimated method retinoscopy values
If accommodative insufficiency is associated:
Low Amplitude of accommodation values as per age
Low Monocular accommodative facility (MAF) and binocular accommodative facility (BAF)
Low Positive relative accommodation (PRA)
If Esophoria is present:
Greater phoria at distance than near
High AC/A ratio
Low Negative fusional vergence (NFV) for distance and near
Low Positive relative accommodation (PRA)
Low binocular accommodative facility (BAF) and difficulty in clearing with minus lens
High Monocular estimated method retinoscopy values
If Accommodative excess is present:
Low Monocular accommodative facility (MAF) with plus there will be difficulty

The Differential Diagnosis

If the conditions are related to CUC and vision, then the clinician should first rule out the presence of non-strabismic binocular vision disorders, because the symptoms are quite diverse in nature for abnormalities with computer usage (Table 2).

Table 2: Visual and Ergonomics symptoms related to Computer User Complex (CUC)

Vision Ergonomics
Eye strain Neck ache
Headache Shoulder ache
Double vision Elbow ache
Pulling sensation around the eyes Wrist ache
Difficulty concentrating on near activity Ankle ache
Blurred Vision Lower backache

If the CUC is a result of any systemic anomalies, then the effect will be acute. Whereas if the CUC is the consequence of vision and ergonomics abnormality, then it will be a chronic condition. Except for visual symptoms, the majority of CUC symptoms that are connected to vision are caused by harmless illnesses. Differentiating the existing binocular vision problem is not too difficult. To achieve this, a thorough examination of all accommodative and vergence parameters is necessary. (4) Ocular inflammation, such as blepharitis and meibomitis, can induce impaired vision following close work. This implies that slit lamp examination is an essential diagnostic in the differential diagnosis of apparent binocular symptoms associated with CUC.(5)

Sequential Management 

  • Correction of ametropia wherever necessary
  • Added lenses if AC/A ratio if affected
  • Exercising Prism if phoria is associated beyond the normal range
  • Vision therapy if accommodative or vergence anomaly is present
  • Ergonomic issues must be taken into consideration (siting position, posture, desk positioning etc.,)
  • Ocular health if there is any ocular pathology associated


Patients suffering from Computer Vision Syndrome (CUC) typically exhibit distressing symptoms that disrupt their ability to focus on school or work tasks. These symptoms are common, and effectively managing these conditions can be a gratifying aspect of optometric care. We emphasise the significance of evaluating all facets of binocular vision, ocular surface health, and ergonomic concerns. Once a precise diagnosis is made regarding the symptoms related to CUC, treatment is usually highly effective. Ocular surface diseases are managed through medical interventions and issues related to workstation setup are resolved through ergonomic adjustments. Binocular vision problems are addressed with the use of various techniques, such as lenses, additional lenses, and vision therapy.



  1. Randolph SA. Computer Vision Syndrome. Workplace Health Saf. 2017 Jul 19;65(7):328–328.
  2. Nichols JJ. Stedman’s Medical Dictionary. 27th ed. 6th ed. Vol. 77. 2000. 284 p.
  3. De‐Hita‐Cantalejo C, García‐Pérez Á, Sánchez‐González J, Capote‐Puente R, Sánchez‐González MC. Accommodative and binocular disorders in preteens with computer
    vision syndrome: a cross‐sectional study. Ann N Y Acad Sci. 2021 May 30;1492(1):73–81.
  4. Scheiman M WB. Clinical management of binocular vision: heterophoric, accommodative, and eye movement disorders. Lippincott Williams & Wilkins; 2008.
  5. Sánchez-Valerio M del R, Mohamed-Noriega K, Zamora-Ginez I, Baez Duarte BG, Vallejo-Ruiz V. <p>Dry Eye Disease Association with Computer Exposure Time Among Subjects with Computer Vision Syndrome</p>. Clinical Ophthalmology. 2020 Dec;Volume 14:4311–7.