The Effect of Computer Eyewear on Viewing Comfort and Performance in Office Work

<Introduction>

When performing near work, one must focus at (accommodate) and point toward (converge) at a closer distance and constantly re-focus the eyes to see small text and images with clarity. Sustaining such efforts can lead to eye fatigue and eye strain, among a host of vision problems. Most visual tasks on a screen also demand heightened visual concentration, and this decreases blink rate. Working in a heated or air-conditioned office environment leads to over-evaporation of the tear film, and lipid deficiency, irritation, and dryness to the corneal surface are expected. Disruptive glare from excessive screen reflection and ambient lighting also deteriorates the image quality and heaps on viewing discomfort. Extensive screen viewing also exacerbates discomfort in people with existing vision problems like eye muscle imbalance, astigmatism, farsightedness, and presbyopia. Since technology is almost unavoidable to modern life, preventions should be taken to lessen the total toll on the eyes and visual system. Gunnar computer glasses address the above issues by providing mild yellow tint anti-reflection coating to shield the harmful blue light and lessen strong glare. The glasses also have a small amount of magnification (+0.5 D) to enhance acuity. The curved frame is designed to retain moisture and reduce dry eye symptoms. All these special characters are devised to enhance visual performance and minimize eye fatigue and visual discomfort in digital viewing. The current study aimed to validate the benefits mentioned above.

Gunnar over-the-counter (OTC) computer glasses adopt yellow lenses to cut off the active short wavelength and lessen the bright glare, which often induces the detrimental effect caused by excessive illumination or intense scattered reflection. While the benefit of glare reduction is well received, the benefit on visual performance has been inconclusive. Some studies reported a significant enhancement in contrast sensitivity, but some failed to see any improvement in visual acuity and contrast sensitivity, even with color distortion. Without argument, tinted lenses reduce the transmittance of the visible spectrum and change the visible color to a certain degree. However, there has been a report that reducing the retinal illumination level does not necessarily lead to reduced brightness; instead, the visual system automatically adjusts for the illumination discounting, possibly with the help of increased pupil size. In addition, with the decrement of blue lights arriving at the eyes, both scattered reflection and chromatic aberration are reduced. Together, it is reasonable to believe that the visual acuity, contrast sensitivity, and chromatic discrimination will not suffer and may, instead, benefit from the filter of yellow lenses. These basic visual functions may, in turn, lead to enhancement in general visual performance such as routine office work. These will be tested in the proposed study.

The current study tested if Gunnar's OTC computer glasses provide any advantages, in comparison to no glasses, on the following aspects in computer-related office work:

• Any enhancement on the visual performance of the basic visual function, including visual acuity, contrast sensitivity, color discrimination, etc.
• Any enhancement on the visual performance of typical office work, including reading, word-spelling check, number searching, or target identification.
• Any benefit in preventing dry eye by measuring the humidity outside and inside the frame (only in the visit with Gunnar glasses) and the tear film break-up time after viewing for a prolonged period.
• Any benefit in objective viewing comfort measured with viewing distance, blink frequency, post-viewing pupil size.
• Any benefit in subjective viewing comfort reflected on the questionnaire of viewing symptom survey.
• Any benefit in viewing comfort and visual performance with increased environmental ventilation.
• Any benefit in viewing comfort and visual performance with increased environment under the intense glare.
• Any benefit in life quality from daily wearing (e.g., viewing comfort, sleep quality, or quantity due to the amount of stimulation from blue light)?
• Their willingness to purchase (select) the tested Gunnar OTC glasses and the price willing to pay for.