We've all heard that beauty is in the eye of the beholder. Turns out, those eyes are beholding beauty differently than they did a generation ago.

Allure magazine recently surveyed 2,000 women and men, just as it did two decades ago, to determine how Americans define what is attractive and sexy. Researchers found that U.S. standards of what is considered beautiful have changed over the past 20 years.

The Allure Beauty Surveys of 1991 and today reveal that while some things haven't changed -- like beauty peaking in our 30s -- other things have. Society's beauty icons have shifted from the stereotypical blond-haired, blue-eyed, skinny model type to one that now embraces darker hair and skin, more prominent features and curvier figures.

Take a look at what Americans said then versus now.

Beauty idol: Then, Christie Brinkley; now, Angelina Jolie

Women's peak age for beauty: Then, women said 34; men said 31. Now, women say 31; men say 28.

Women's peak of sexual attractiveness: Then, women said 32; men said 30. Now, women say 31; men say 28.

Men's peak age for handsomeness: Then, women said 35; men said 33. Now, women say 34; men say 31.

Men's peak age of sexual attractiveness: Then, women said 33; men said 31. Now, women say 34; men say 30.

How important is physical appearance in attracting a significant other? Then, 37 percent of women said it was important. Now, 51 percent of women and 52 percent of men say it is either very important or the most important thing in attracting a mate.

Other important findings included:

Celebrity Icons

• As to name the most beautiful males, both men and women include Brad Pitt, George Clooney, Tom Cruise, Denzel Washington, Ryan Reynolds, Matthew McConaughey, Harrison Ford and Hugh Jackman in their top picks.

• For most beautiful female, both men and women include Angelina Jolie, Halle Berry, Megan Fox, Beyoncé, Jennifer Lopez, Julia Roberts, Sandra Bullock and Jessica Alba in their top picks.

Beauty Preferences

• 64 percent think women of mixed race represent the epitome of beauty.

• 70 percent of those who wish to change their skin color wanted it to be darker.

• 74 percent of those surveyed believe that a curvier body type is more appealing now than it has been over the past 10 years.

• 69 percent of survey respondents believe there is no such thing as an "all-American look."

Racial Differences

• African-American and Hispanic women are twice as likely as Caucasian women to report
not wanting to change their body in any way.

• African-American and Hispanic women are more likely than Caucasian women to feel
they're more attractive than their significant other.

• A third of African-American women think of themselves as the most attractive person in
the room.

• African-American men are directionally more likely to embrace and aspire to curviness. They say they want women with curvier hips and a higher/rounder butt or a larger butt.

The Age Factor

• The younger the male respondent, the more likely he is to agree with the statement "cougars are hot."

• 86 percent of everyone surveyed think that middle-aged women of today are perceived as more attractive than they were two decades ago.

What do you find most attractive in a man or woman? Tell us what you think!

Know what else is hot? Healthy, glowing skin. Check out these tips!