Soap - and sometimes 'natural' products (like Aveda) can easily be a cause of contact dermatitus. I think the soap on AA is very harsh and don't use it myself as I have allergies to lavender and some other fragrences. I recall eyeing the bottle with suspicion when they first went to Aveda products. (Many people think 'natural' = less harsh - HA!). Many of these products include essential oils which add scent but are very irritating to many people.

Your eyes many be very dry from the lack of humidity in flight. Moisturizing eyedrops can help (not Visine - more like Natural Tears).