...Then look at the backs of the hands...
Cosmetic plastic surgery and careful makeup can make the face superficially appear 15, maybe 20 years younger; and hair technology can do much the same.
But so far, nothing much can be done to the backs of hands except to cover them, keep them out of sight or - for celebs - photoshop/ defocus/ smear vaseline on the lens.
The backs of hands have thin skin with only just enough to allow the fingers to bend (so, no possibility of nipping or tucking); and they typically collect a lot of sun damage in a time-linear accumulation (especially from those who like to sport a sun tan - exactly those most likely to use plastic surgery to create a more youthful appearance).
So (assuming you know what to look for - e.g. including subcutaneous-fat thinning, as well as sun damage) skin condition on the backs of hands tend to be a highly sensitive and reliable measure of chronological age - even distinguishing girls in their late teens from those in their early twenties. Indeed, under normal circumstances*, it is the only reliable index - which is why so many older women trying to pass as younger wear gloves, on the slightest excuse or none
Such is our societies fear and loathing of age - especially among women but strongly increasingly among men - that if/ when it became technologically possible to live one's life in a virtual-simulated young-attractive 'skin suit' - there would be many, many takers; despite the reality a increasingly decrepit body within.
For secular hedonic modernity, honesty has been discarded as a value, expedience is all, and deception is limited only by fear of detection.
Appearance is everything; it is the only 'reality'.
*Note: If a woman was to wear gloves or total sun block on the backs of hands from early childhood, this would greatly delay the signs of skin ageing - the skin of the buttocks usually appears less-aged for many-more years than the hand backs, for this reason.