In a business setting, upon encountering women with aggressive cleavage, where is the proper place to fix one's gaze in order to maintain a professional demeanor?

Further: how does a person accomplish such a thing without being obvious about the avoidance?

In my new position I'm regularly sent into the offices of high-profile clients. We're talking about lobbying firms with partners who rub elbows with Congressmen; communications firms that brief Obama's cabinet and captains of industry on how to behave on camera; lawyers who spend a lot of time at the Supreme Court... you get the idea.

A shocking percentage of these offices are very old-fashioned about how the partners are coddled and cared-for: they basically have a bevy of young, attractive assistants who do everything from reading the partners their email to picking out bottles of scotch for Senator so-and-so.

I spend a lot of time with these young ladies since they are always the ones who have to figure out computer/Blackberry/printer/television/motorized tie rack problems for the partners. Every last one of them dresses provocatively. I don't think they're doing it entirely on purpose (and certainly not solely for my benefit), but there is still cleavage left, right, and center all damn day long.

I feel like they can tell I'm making a conscious effort to look them in the eye when we talk. And I'm not even pretending like that's an easy thing to do. Most of the time if I can remember 5% of what they were going on about, I'm doing well. I try very hard to get them to show me what they were doing on the computer/iPhone/copier/toaster oven so I can at least pretend to focus on the problem. The worst is when they want me to look over their shoulder at Mr. Namesonthedoor's new Galaxy SIII that won't sync... right behind that is when I have to face them over a low cubicle wall or divider.

In my head I'm thinking dontlookdownhershirt dontlookdownhershirt youllgetfiredsofastyourheadllspin forgodssakesdontlookdownherfarkingshirt so hard I'm sure these girls can hear it. Staring them right in the eyes doesn't help much when my--not peripheral, since it's usually more of a downward direction, what do you call that?--field of vision includes the jigglies. What the hell am I supposed to do?

tl;dr: bewbs!