In reply to AlH: I sent the link to the blog to my father, it brought back some memories apparently: Been there - on the Isle of Skye during a wet summer in the late 1960s.
Unless you have experienced it you can have no idea about the impossibility of dealing with an intense midge swarm for any length of time.
I have sat inside by tent wearing a baraclava and a hanky over my mouth to filter midges out of my tea. I have seen a guy run screaming from his tent and dive into the sea to get out of the swarm.
Deet is, at best, a limited answer, a special head-net and complete body coverage is the only real answer. We climbed onto the Skye ridge and bivied on a summit where the wind kept them away on one occasion.
Scottish tourism's greatest challenge?