You should always learn about the merits and demerits of eye creams before buying and using them.
This gives you a clear idea of the consequences and side effects (if any) of its use.
Since eyes are very sensitive, it should be made sure that whatever eye cream you use, it should not affect your eye in any case.
Different eye creams have different types of problems as far as the demerits are concerned.
It is very important to follow the guidelines of its usage.
The proper amount as prescribed by the doctor should be used and not in excess.
Excess of the cream might have adverse affect on the eye.
Also, it should not be in contact with the extra sensitive regions of the eye.
Proper care should be taken in that case.
The merits are that if applied according to what has been prescribed then the positive effect is optimized.