"I am the cast. You're looking at her," Light said in an interview that aired today on "Good Morning America." "It's really challenging. It's daunting."
Light, 67, stars in "All The Ways To Say I Love You," an off-Broadway play about love, hard choices and the cost of fulfilling all-consuming desires.
"There is definitely stage fright," Light said. "There's also excitement. It's such an interesting, fascinating piece."
In her new role, Light plays a retired high school English teacher and guidance counselor in a loving marriage. Light's character recounts her past experiences, revealing the truth beneath the many details of her life.
As the actress looked back on her own career, she said she's managed to defy traditional limitations.
"My career has gotten better," Light said. "I have gotten more interesting parts as I have matured."
Light said that although it can be rare for a female actress to be able to say that, she believes the perception toward older female actresses in Hollywood is changing.
"The more women who are speaking about it and talking about themselves as mature instead of hiding it or trying to closet it, in some way we're making a path forward for the women who are younger in the business," she said.
"All The Ways To Say I Love You" opens Sept. 6, at the MCC Theater in New York City.