These are nazar, glass type  - not plastic nor resin -  evil eye beads from Turkey. It is made to wear for protection on yourself as "evil eye or envy eyes" are indeed real and they can curse people which can sometimes be unintentionally or deliberately, may it be from strangers or from people we love. It is essential to wear one to protect yourself. 
Putting an anklet to your left feet is also helpful to protect yourself from wandering apirits as your left area is always a passage through for evil to go through. Though personally, I have this on both my feet... and I don't ever remove it as well. Though for the longest time, I have it on my left leg and it changed my life. I would randomly feel sluggish and sick before, as I do tend toe asily absorb things so just this one little thing change everything for me. I know not everyone will feel the same way but I know it will benefit people and since it directly came from Turkey, I can assure its authenticity. :) Do be assured that this will protect you.
No need for prayers to do. Just wear it and don't take it off even when you shower. And let it be there until it gets cuts off by itself (usually a sign that it is at its limit). Until then, be at ease that you are in safe hands. ;)