Tired eyes, strain, headache, redness, burning or tearing - all of these are classic symptoms of both digital eye strain and dry eye syndrome. These conditions overlap so much because multiple studies have shown that looking at screens disrupts our natural blink rate, causing dry eyes. But can treating dry eyes with the most common first line treatment, over the counter artificial tears, provide adequate relief of device related eye strain and discomfort? A new study published in Scientific Reports explored just that: 

The Study Set Up

30 adults (11 men, 19 women) with digital eye strain and dry eye symptoms (as confirmed by the Computer-Vision Symptom Scale CVSS17 and the Ocular Surface Disease Index OSDI respectively) were enrolled, all reported screen use of at least 4 hours a day. Treatment with Systane Ultra preservative free artificial tears four times a day was initiated at the initial visit where baseline testing was performed, and then testing was repeated at both 1 week and 1 month visits.

At each visit patients had symptoms assessed with both the CVSS17 and OSDI tests, as well as objective dry eye measurements of non-invasive tear break up time, tear meniscus height, and blink rate.  Visual performance was also assessed during these visits; eye fixation was tracked while performing computer tasks, and both silent and out loud reading speed was scored. 

At the end of 1 month there was a statistically significant improvement in symptom scores on both the OSDI and CVSS17 tests using Systane Ultra 4 x day. 

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So using high quality artificial tears 4 times a day did improve symptoms, but did any other score or performance metric improve? Not in this study. Noninvasive tear break up time had no statistically significant changes. In principle this is a measure of the amount of tear film produced by the person, and we know that using over the counter artificial tears doesn't change the amount of tear film your own body makes. Tear meniscus height temporarily increases when you first put a drop in, but after performing computer tasks there was no significant difference in this value versus baseline. So the take home for dry eye treatment: artificial tears can improve comfort and symptoms, but they won't change how much tear film your body actually produces.

What about visual performance? Outloud reading speed was assessed by having patients read a 77-word International Reading Speed Text from a computer screen and then converted to a normalized value (words per minute/average expected speed). No statistically significant difference was found in reading speed was found from baseline to the final visit. There was also no difference found in blink rate or eye fixation in this study after 1 month of artificial tear use.