An everyday habit during a long-haul flight could have painful consequences for certain travelers — with a recent case highlighting some serious dangers. The dry air inside an airplane cabin, combined with hours spent wearing contact lenses during a long travel day, can leave the lenses with less moisture and eyes feeling increasingly uncomfortable, experts say.In some cases, irritation or damage to the surface of the eye can lead to more serious problems.FLIGHT ATTENDANTS BEG TRAVELERS TO STOP DOING THE ONE THING THAT ANNOYS CREWS MOSTOne traveler recently described temporarily losing vision in one eye after returning home from an international trip, according to the New York Post.The woman said she wore her contact lenses throughout an 11-hour flight home from Greece and for roughly 24 hours of travel — while also wearing them while swimming and showering, according to the outlet.Wearing contact lenses while traveling can cause painful eye problems, especially on long flights.The problems can be serious, experts say. (iStock)Within days of returning home, the traveler developed pain and sensitivity to light before her vision significantly worsened. Doctors eventually diagnosed her with a corneal ulcer. She underwent weeks of treatment with eye drops and was left with a small scar that continues to blur part of her vision, the outlet reported.The traveler developed pain and sensitivity to light before her vision significantly worsened. Valerie Kattouf, an Illinois-based optometrist, told Fox News Digital that wearing contacts during extended flights can increase dry-eye symptoms and lead to irritation, a "sandy, gritty feeling" and intermittent blurred vision.CLICK HERE TO SIGN UP FOR OUR LIFESTYLE NEWSLETTER"The cabin air has significantly reduced humidity that can actually remove moisture from the contact lens and create more dryness," Kattouf said.Wearing contacts during extended flights can increase dry-eye symptoms and lead to irritation, a "sandy, ...