What we know is that each May a few individuals visiting Iceland suffer from the effects of haze whilst others apparently do not. The effects are illustrated in the pictures below - an example of what normal people see (a typical white-red sequence) and what people unaffected by haze see (pic 2). A further possible contributing factor included in picture 3.
More sleep, less booze and younger eyes are longer term fixes. Initial tests have suggested that large quantities of ice cream or Skyr may moderate effects in the short term. We'd be interested in your views on this issue. Have you suffered? Can you read rings at > 50m in sunlight? Does age matter?