[Research] How much the skin care products being in a jar decrease the ingredients' effect?

Beauty Tips For Body Care
I have read many times how the effectiveness of the ingredients gets decreased when the product is bottled in a jar because of the light and air exposure, and get more prone to develop bacteria. My question is how much? Is there a detailed report you know?It makes sense to me a 30-50ml face moisturizer in a wide jar is bad news if it will last for months. The cream will be exposed to air and light every time you open the jar for months. But what about eye creams for example? Most of them already come in 15ml, so quite small. For me an eye cream lasts for only about 2 months. Would the ingredients really lose their effect in 2 months?I ask because I really love the texture of Clinique All About Eyes and it moisturizes my eyes well. But it's in a jar, if I get nothing other than moist that comes with the oil, the price will be too much. I can't decide if I should purchase it or just go with an eye cream in tube/bottle.
Girls Blog 2015
Submitted by Redhaired103