What action did Vincent take to change his eye color?

Vincent chose to wear colored contacts to change his eye color, which is a simple and non-invasive method to alter one’s appearance temporarily. This choice aligns with his desire to blend in and avoid discrimination in a society that places great importance on genetic perfection and specific physical traits.

Unlike surgical alterations or special eye drops, which imply more permanent and invasive changes, colored contacts allow immediate, adjustable alterations without significant risk. This approach reflects Vincent's resourcefulness and determination to overcome the challenges posed by societal expectations in the world of GATTACA, where genetic engineering dictates many aspects of identity and opportunity.

By using colored contacts, Vincent could visually present himself in a way that suited his needs without undergoing the more drastic measure of surgery or relying on fictional methods like special eye drops, which do not exist in conventional practice. Ultimately, this choice emphasizes the themes of identity, disguise, and societal pressures within the storyline.