I'm 23 and i thought i should start using anti-aging products, is it advisable at this age? what about retinol and can it be applied under the eyes?

The best anti-aging: Effort is to live a moderate, healthy life-style with proper food choices, proper rest, proper levels of work activity & enjoyment, non-polluted water and air, non-irritating materials, etc. It's the best anti-aging thing you can do. Products carefully chosen may not harm you, but they'll not do more than that. If you follow the directions on a high quality retinol face product you should be fine.

Retinol: At age 23, you probably do not need to use anti-aging products. However, most retinol creams are safe near the eye-- just make sure not to put any cream in the eye itself.