It's all in the eyes! Scientists can tell whether someone is straight or gay by studying optical reflexes

Cornell University research shows pupil dilation may indicate sexual inclinations

Is he or isn't he?



New research could end the misery of trying to read the signs of someone's sexual orientation.

Scientists say a person's pupil will shoot open when they become aroused, helping those on the prowl know whether or not they will get lucky.



Eye-le! The secrets of a person's sexuality is hidden in their eyes, a new study reveals

Pupil dilation has long been known to track the level of someone's excitement. Pupils open slightly when a person sees a puppy dog or a friendly face.

But now researchers say reading optical reflexes could solve the conundrum of guessing which team a person is playing for.



The sex study, conducted by Dr Ritch Savin-Williams and Gerulf Rieger of Cornell University, monitored 165 men and 160 women, including gay, straight and bisexual participants.



The subjects' pupils were studied as they screened one-minute videos of a man masturbating, a woman masturbating and neutral landscape scenes.

Optical disclosure: New research from Cornell University suggests pupil dilation is an accurate indicator of sexual orientation

Straight men reacted to sexual images of women, gay men responded to sexual images of men and bisexuals respond to both men and women, the results showed.

But women, in traditional fashion, were far more complex.

Gay females had pupil dilation after seeing sexual images of other women but straight women dilated similarly in response to erotic images of both sexes.

This doesn't mean that all straight women are secretly bisexual, Dr Savin-Williams warned, just that their subjective arousal doesn't necessarily match their body's arousal.

Sex researchers can't explain why this would be but some theorize the response is a survival mechanism given the risk of female rape. A woman's body could respond to a sexual stimulus, regardless of its appeal, for her own protection.