ALL RIGHT! In fact we can choose from these sides.
If you are healthy eyes you can choose the HAMA
And IF you are Sensitive eyes you can choose the material inclouding of SILICIOUS.
If you are small eyes so you can choose the samll one ,the diameter can be choosed about 14.0mm.
And If you like big eyes and the eyes themselves are big, SO you can choose the diameter about 14.2mm or 14.5mm.
According these two pictures, you can find the effect about the big diameter and small diameter.