We all know 'bedroom eyes' when we see them: it's the look of lust. There's just one thing you need for bedroom eyes: big pupils. According to 'pupillometrics', the science of pupil study, this is the crucial element we respond to. You can't consciously control your pupils (one reason why people say the eyes don't lie). But you can create the right conditions to inspire large pupils and get the effect.
First, reduce light. Our pupils expand when they're robbed of it, one reason why candlelight and dimmer switches are de rigueur in romantic restaurants. It's not just the softening of light that makes our faces appear more attractive, larger pupils also help.
Scientists showed two sets of pictures of a woman's face to men. The photograph was identical, except for one thing; the pupils in one set had been doctored to make them larger. When shown the doctored photograph, men judged the woman as twice more attractive than when shown the real photo. It was repeated with a man's face and tested on women and gave the same result.
Our pupils also enlarge when we look at something we like. Again, this can be proved using pictures. This time, researchers put a picture of a naked woman into a pile of otherwise bland, commonplace photographs then watched men's pupil size when they flicked through them. Without exception, the men's pupils expanded on cue.
This means if you're attracted to someone a lot, your pupils are probably already big, black holes. All good. To ensure this is happening or to up the effect of your bedroom eyes, focus on the part of the person you like the most.