The Influence of Eye Solutions on Blinking and Ocular Comfort at Rest and During Work at Video Display Terminals

doi:10.1006/exer.1998.0656

Experimental Eye Research

Volume 68, Issue 6, June 1999, Pages 663-669

https://doi.org/10.1006/exer.1998.0656 Get rights and content

Abstract

The aim of this work was to study blink frequency changes and levels of ocular discomfort during work at a video display terminal, and the effects on these parameters of augmented or reduced humidification of the ocular surface.

Blink rate was measured from recordings of the electrical signal evoked by the contraction of the orbicularis oculi muscle. Blink rate and interblink intervals were analyzed at rest and during performance of a task with a computer (playing a card game) for 10 or 30 min in steady environmental conditions and during application of a continuous stream of air to the face. In two separate sessions, the effect of pretreatment with humidifying ocular solutions of different elastoviscosity (balanced salt solution or elastoviscous 0.1% Hylan A solution) was assayed. At the end of each experimental period, the subjects marked the level of ocular discomfort experienced on a 0–10 cm visual analogue scale.

The blink frequency at rest (12.4±1.2 blinks min⁻¹) was reduced significantly (to 10.3±1.1 blinks min⁻¹) by pretreatment with elastoviscous eyedrops both with and without air applied to the face. This effect was not obtained with balanced salt solution. During performance of the visual task for 10 or 30 min, basal blink rate decreased significantly, to about 40% of the control value. Neither application of an air jet on the face nor application of eye solutions of different viscosity modified this reduced blink rate.

A low degree of ocular discomfort developed after performance of the visual task that was enhanced by air application to the face. This discomfort was reduced by pretreatment with ocular solutions, the elastoviscous eye solution being more efficient than the balanced salt solution. Interblink interval duration was also more regular after treatment with the elastoviscous solution.

These data suggest that blink rate at rest is maintained in part by activation of sensory receptors of the cornea and conjunctiva, which are stimulated by desiccation of the ocular surface. Reduction of eye blink frequency elicited by the performance of a visual task with a computer appears to depend on central neural mechanisms that are quite independent of peripheral sensory inputs. The reduction of blink frequency consecutive to computer use was associated with a sensation of discomfort that was attenuated more effectively by elastoviscous eyedrops than by regular balanced salt solution.

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^f1: Address correspondence to: M. Carmen Acosta, Instituto de Neurociencias, Universidad Miguel Hernndez, Campus de San Juan, Aptdo. 18, 03550 San Juan de Alicante, Alicante, Spain.

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Regular articleThe Influence of Eye Solutions on Blinking and Ocular Comfort at Rest and During Work at Video Display Terminals

Abstract

Am. J. Ophthalmol.

Ophthalmology

Int. J. Psychophysiol.

Exp. Eye Res.

Psychiatry Res.

Am. J. Ophthalmol.

Corneal nociceptors

Excitation by irritant chemical substances of sensory afferent units in the cat's cornea

J. Physiol.

Possible health effects of working with VDUs

Br. J. Ind. Med.

CO2stimulation of the cornea: a comparison between human sensation and nerve activity in polymodal nociceptive afferents of the cat

Eur. J. Neurosci.

Ocular surface temperature

Curr. Eye Res.

Eyelid movements

Invest. Ophthalmol. Vis. Sci.

Response of sensory units with unmyelinated fibers to mechanical, thermal and chemical stimulation of the cat's cornea

J. Physiol.

Tear film physiology

Am. J. Optom. Physiol. Opt.

Regular article
The Influence of Eye Solutions on Blinking and Ocular Comfort at Rest and During Work at Video Display Terminals

CO₂stimulation of the cornea: a comparison between human sensation and nerve activity in polymodal nociceptive afferents of the cat