Digital eye strain is a collection of ocular and non-ocular signs and symptoms that occur due to prolonged use of visual display units.1 This condition was previously called computer vision syndrome but had to be changed because visual display units are present in other digital devices such as mobile phones and game consoles. Digital eye strain can manifest in various ways, including vision-related strain, oculomotor strain, ocular surface strain, environment-related strain, and device-related strain. According to a report by The Vision Council, 65% of the American adult population who use digital devices experience digital eye strain.2 The symptoms associated with digital eye strain include frontal headaches, tired eyes, focusing difficulties, diplopia, dryness of the eyes, burning sensation, and even neck and back aches.1 The symptoms associated with digital eye strain can be similar to those of other eye conditions. For proper diagnosis, eyecare practitioners must look for a combination of visual disturbances that the patient experiences while using digital devices.
Research has indicated that prolonged use of digital devices can lead to alterations in accommodative lag, facility, and recession of the near point of convergence. These changes may lead to asthenopic symptoms, altered posture to compensate for near viewing problems, and receded near point of convergence or accommodation. Posture adjustments to compensate for these issues eventually leads to back and neck aches.
Contact lens wear in an individual experiencing digital eye strain may increase the risk of worsening the condition, particularly if contact lens discomfort is already present.
Inserting contact lens into the eye disrupts the tear film, splitting it into the pre- and post-tear lens Contact lenses are also inflammatory. Put simply, when a contact lens is inserted into the eye, all the classic signs of inflammation occur.
Redness of the eyes (rubor) has been identified as the second most common reason next to discomfort for discontinuing contact lens wear.3 And compared to non-contact lens wearers, contact lens wearers have a higher surface temperature4, with silicone hydrogels inducing higher temperatures compared to hydrogel contact lenses (calor). The issue of cornea swelling after insertion of a contact lens into the eye, although subtle, can be easily verifiable by noting the change in cornea thickness before and after contact lens wear. Note the appearance of the striae (which represents 5% edema) or folds (representing about 8% edema) on the cornea and guttate changes on the endothelium (tumor).5 The effects of contact lens wear on digital eye strain can also be viewed from the lens of the relationship between hypoxia, cornea swelling and inflammation.
A significant proportion of contact lens wearers experience decreasing comfort with contact lens wear towards the end of the day with the suspected culprits being sub-clinical inflammation and stimulation of nociceptive receptors on the ocular surface (dolor).6 These symptoms can be exacerbated and lead to function loss(functiolaise). As Nathan Efron6 notes, the removal of contact lens due to discomfort constitutes loss of function which has also been identified as the main reason for contact lens dropout.
From the above points, when wearing contact lenses, a sub-clinical inflammation may occur. Unlike microbial keratitis, this inflammation should not be viewed negatively as it does not lead to tissue destruction. Instead, it prepares the eye to fight against any harmful agents that may come in contact with the ocular surface. However, this inflammation can cause discomfort for contact lens wearers, and clinicians should be aware of the signs.
Wearing contact lenses and using digital devices can lead to a decrease in blink rate. When contact lens wearers frequently use digital devices, they may experience eye strain and discomfort. A recent survey found that contact lens wearers who experienced digital eye strain were more likely to experience discomfort than non-contact lens wearers.7
Management
In managing contact lens discomfort and digital eye strain, the evaluation of the patient must include binocular vision assessment and dry eye/ocular surface evaluation in addition to routine eye tests.
To manage digital eye strain in contact lens wearers, it’s important to first address the root causes. This means practicing good ergonomic habits when using digital devices, taking frequent breaks (such as using the 20-20-20 rule), blinking often, maintaining proper lighting and posture. Although the 20-20-20 rule may not be sufficient to tackle digital eye strain,8 taking frequent breaks and optimizing ocular surface health and oculomotor system health can help alleviate symptoms.
In addition, contact lens wearers experiencing digital eye strain should undergo several tests to assess the ocular surface health together with routine and binocular vision tests. These tests may include near point of convergence and accommodation, accommodative convergence ratio, phoria testing, accommodative response (lag/lead), vital dye staining, tear break up time test, and evaluation of the eyelids and meibomian glands.
Figure 1: Image of unstable tear film during fluorescein tear break-up time test. Image courtesy: Dr Obinwanne
Further management may include prescribing low near addition spectacle lenses with anti-glare and other coatings, artificial tear drops for dry eye disease and even vision therapy.
For contact lens wearers with digital eye strain, after ensuring ocular surface health is optimized, switching from hydrogel to silicone hydrogel contact lenses has been shown to induce less limbal and conjunctival redness owing to better oxygen transmissibility and less hypoxia.9 Frequent replacement lenses such as daily disposables may be of benefit.
For daily-wear contact lens wearers, contact lenses with excellent wetting technology, low water content, high oxygen transmissibility, and ocular surface-friendly care systems such as peroxide solutions are preferred. Prescribe a multifocal lens with the above features for a presbyopic contact lens wearer experiencing digital eye strain. Low-addition silicone hydrogel contact lenses are ideal for non-presbyopes experiencing digital eye strain. One such lens is the Biofinity Energys from CooperVision which has a low addition of +0.3D, with the comfilcon A material and Aquaform technology that maintains the lens wetting properties and hydration. This lens allows for comfortable wear and addresses changes to accommodative lag and vergence issues associated with digital eye strain.
It can be difficult to distinguish between discomfort caused by contact lenses and digital eye strain. However, by careful history and identifying the signs and symptoms of each issue, we can address any anomalies and improve the quality of life in our patients.
REFERENCES
- Coles-Brennan, C., Sulley, A., & Young, G. (2019). Management of digital eye strain. Clinical & experimental optometry, 102(1), 18–29. https://doi.org/10.1111/cxo.12798.
- The Vision Council. Eyes Overexposed: The Digital Device Dilemma. Digital Eye Strain Report 2016.
- Dumbleton K, Woods CA, Jones LW et al. The impact of contemporary contact lenses on contact lens discontinuation. Eye Contact Lens 2013; 39: 93–99.
- Purslow C, Wolffsohn JS, Santodomingo-Rubido J. The effect of contact lens wear on dynamic ocular surface temperature. Cont Lens Anterior Eye 2005; 28: 9–36.
- Efron N. Stromal oedema. In: N Efron, ed. Contact Lens Complications, 3rd edn. Edinburgh: Elsevier, 2012. p 185–197.
- Efron, N. (2017), Contact lens wear is intrinsically inflammatory. Clin Exp Optom, 100: 3-19. https://doi.org/10.1111/cxo.12487.
- González-Méijome J, Parafita M, Yebra-Pimentel E et al. Symptoms in a population of contact lens and noncontact lens wearers under different environmental conditions. Optom Vis Sci 2007; 84:E296–E302.
- Johnson, S., & Rosenfield, M. (2023). 20-20-20 Rule: Are These Numbers Justified?. Optometry and vision science : official publication of the American Academy of Optometry, 100(1), 52–56. https://doi.org/10.1097/OPX.0000000000001971.
- Covey M, Sweeney DF, Terry R et al. Hypoxic effects on the anterior eye of high-Dk soft contact lens wearers are negligible. Optom Vis Sci 2001; 78: 95–99.
