A Mayfly Dun's Eyes

[Byron haugh]

Well, this is something that has "bothered" me (more accurately piqued my interest) for the last 40 years and I have never tried to get an explanation to date.
Thought I might try now.

Some of the hatches of sub imago insects (particularly the males) have extremely pronounced eyes.

Now, in tying, most tiers (myself included) will say: "tie off a neat head".

Anyway, what I am trying to figure out is: Why do we tie off a neat head vs. something that looks similar to the insect's head (eyes actually)?

Has anyone else wondered and, if so, what is your conclusion.

This photo is of a March Brown from Troutnut.com