Vernal Keratoconjunctivitis Worsened By Sunlight, Digital Device Use

Sunlight and bright computer screens may trigger vernal keratoconjunctivitis symptoms.

Sunlight and the bright screens of digital devices may affect the severity of symptoms for patients with vernal keratoconjunctivitis (VKC), according to research published in the World Allergy Organization Journal. 

Researchers used the COVID-19 lockdowns as an opportunity to investigate the impact of reduced sunlight exposure in patients with VKC. They included 29 boys (mean [SD] age, 8.74 [2.40]) in the retrospective analysis. Participants underwent slit lamp and anterior segment analysis. An ophthalmologist assigned sign scores for conjunctival hyperemia, conjunctival tarsal or limbal papillary reaction, trantas dots or corneal superficial keratopathy (0, absent; 3, severe) and collectively added the scores for a single sign score (range, 0-12).  

Participants reported symptoms of photophobia, tearing, ocular itching, and mucus secretions through a 10-point visual analogue scale (VAS; 0, no symptoms; 10, worst symptoms) and scores were collectively added for a single VAS score (range, 0-40). Patients also reported the number of hours spent using devices with bright screens and disclosed whether their home had a garden to assess the effect of potential sunlight exposure. 

We can conclude that exposure to nonspecific triggering factors such as sunlight and bright light screens is a favoring factor for conjunctival inflammation trigger in VKC.

A comparison of analyses taken in 2019 and 2020 revealed no statistically significant differences in VAS or severity scores, according to the report. In total, 34.4% patients benefited from the lack of sunlight exposure and presented symptoms upon re-exposure. Overall, patients spent a mean of 1.95 hours per day using bright screens in 2019 and increased usage to 4.14 hours per day in 2020 (P =.048), but there were no significant differences in use among patients with mild, moderate, or severe VKC symptoms. However, a subgroup analysis of patients who presented with symptoms upon re-exposure to light revealed that a 4 times or less increase in screen time resulted in a reduction in symptom severity. 

“We can conclude that exposure to non-specific triggering factors such as sunlight and bright light screens is a favoring factor for conjunctival inflammation trigger in VKC,” according to the researchers. “Our results suggest that use of sunglasses, hats with visors and swimming goggles should be recommended, as well as the reduction of time spent in front of bright light sources such as smartphones, computers, television in children with VKC.”

Study limitations include a small sample size and the strict inclusion of boys in the study sample.


Cristina AM, Mariacristina E, Marta S, et al. The effect of COVID-19 imposed lockdown on Italian children with vernal keratoconjunctivitis. World Allergy Organ J. Published online September 7, 2022. doi:10.1016/j.waojou.2022.100701