Do Gunnar Glasses reduce eye strain?

Question

In my RSS feeds today, I got an article named Gunnar Glasses Reduce Computer Eyestrain, Are 75% Off for the Next Two Days which links to a previous article about their benefits:

Gunnar's website claims they protect your vision by filtering out "artificial" light, and relaxes your eyes, so you get tired slower. They also claim that it prevents dryness, but I'm not quite sure how it would go about doing that, since the glasses aren't like those James Worthy or Horace Grant goggles that encase your eyes—they're just normal glasses.

On Gunnar's own website, they claim:

GUNNARS increase contrast, comfort and focus while minimizing eye fatigue and visual stress for anyone who spends long hours staring at digital screens. GUNNAR eyewear is powered by i-AMP lens technology comprised of a proprietary lens material in an advanced geometry tuned for intermediate viewing distance and finished with custom formulated lens filters, tints and coatings.

For specific claims (that seem relevant):

• Improve contrast and filter out UV.

  IONIK lens tints improve overall contrast and comfort by filtering out harsh artificial light, eliminating UV rays and reducing high-intensity visible light.

• Anti-reflective.

  iFi lens coatings include an anti-reflective layers to reduce glare and an exterior hard coat that minimizes environmental damage and scratching.

• Improved detail/focus.

  FRACTYL lens geometry includes a specifically tuned focusing power to enhance detail and a highly wrapped lens design that limits air currents near the eye.

Is there any evidence that these things actually reduce eye strain or fatigue? Or that they're beneficial at all?

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I've seen a couple more articles about this recently, but they seem to be providing evidence that Gunnars are better than low-quality glasses, but they market them primarily to people who don't need glasses, so I think the relevant claim is that "wearing Gunnar glasses is better than not wearing glasses".

Answer 1

They may be beneficial from the American Optometric Association:

Eyeglasses or contact lenses prescribed for general use may not be adequate for computer work. Lenses prescribed to meet the unique visual demands of computer viewing may be needed. Special lens designs, lens powers or lens tints or coatings may help to maximize visual abilities and comfort.

The lens powers and tints or coatings are what the Gunnar glasses are providing.

Also an opthamological literature review reveals that:

The occasional computer viewer may be able to get away with using their general eyewear, but those who spend more than one hour a day, including the occupational user, can benefit from the use of computer glasses. The trick is in choosing the right type. Computer Vision Syndrome: A Review, Blehm, et al 2005

And

Color-contrast optic filters are known to improve the color discriminating capacity when exposed to video display terminals. Feigin et al revealed that 20 of 23 subjects reported an improvement of visual fatigue after 4 weeks of using the eyeglasses with spectral filters.1

The abstract of the referenced article states:

Color-contrast optic filters are developed for improving the color discriminating capacity of eyes exposed to video display terminals. These filters are applied as a coating on correcting or common glasses. Effects of such eyeglasses on visual functions accommodation, frequency-contrast sensitivity, and critical frequency of flashes fusion (CFFF) were studied in 23 PC users with visual acuity of 1.0 with correction. Wearing of eyeglasses with filters promoted shifting of the most distant point of clear vision further and increased the accommodation volume, contrast sensitivity at the low and decreased it at the medium and high frequencies. CFFF was not changed. Wearing of eyeglasses with filters for 4 h of working at a display caused shifting of the nearest and most distant points of clear vision in comparison with the control group with the accommodation volume unchanged and preserved the high contrast sensitivity at the mean and low frequencies during the entire period of work. No changes in CFFF were noted. After 4 weeks of using eyeglasses with spectral filters, 86.9% of volunteers noted an improvement of visual working capacity and 13.1% considered there was no difference. Hence, eyeglasses with spectral filters are recommended as an ophthalmological measure preventing visual fatigue during long work with video displays.Prevention of visual fatigue in computer users by eyeglasses with spectral filters, Feigin, et al 1998