Could figuring out if someone is straight or gay be as simple as looking into their eyes?

According to a new study released by Cornell University, pupil dilation is an accurate indicator of sexual orientation.

Researchers used a specialized infrared lens to measure changes in pupil size. They discovered that when people look at erotic videos, their pupils widen.

"We wanted to find an alternative measure that would be an automatic indication of sexual orientation, but without being as invasive as previous measures,” explained Gerulf Rieger, the study's lead author and research fellow at Cornell. “Pupillary responses are exactly that."

He added, ‘”With this new technology we are able to explore sexual orientation of people who would never participate in a study on genital arousal, such as people from traditional cultures. This will give us a much better understanding of how sexuality is expressed across the planet."

However, critics say there is a drawback, claiming that people can learn how to suppress their arousal; therefore, preventing any change at all in their pupils.

The findings were published on August 3 in the scientific journal PLoS ONE.