Allergy patterns have changed in the 30 years Professor Stephen Till, Consultant Allergist at Allergy London, has been studying them. “There’s been a significant increase in tree pollen, to the extent that we get many more patients with bad symptoms in early spring, but also the summer,” he says. “It’s much more common to be allergic to trees as well as grass now.”

Recent figures on ocular allergies are hard to come by, but one paper suggests that 8% of nearly 2,000 patients attending optometry practices in the West Midlands reported an ocular allergy (Wolffsohn et al, 2011 ). “As an estimate, roughly a third of the UK population has some degree of hay fever,” Stephen says. “And probably up to half of those have annoying eye symptoms as part of that.”