Maybe it's because they are the windows of the soul in first life, but I have never been quite satisfied with the eyes I have in Second Life.
More than any other buyable attribute, they can go so wrong... be too small, be too shiny, be too hard, or be too blank in the middle. I have dozens and dozens of eyes in my inventory, but none of them really satisfied me.
Then this morning I stumbled upon Wild Lilies in Second Life, billed as the biggest eye shop - and I think that's probably right. I haven't seen another which comes even close to this.
I found the perfect eyes for me here - the soul series is big enough, with the right amount of shininess, the right size of pupil, the right depth of reflection. I'm very pleased. All my other eyes are going in the trash bin!