Volks USA
This should be your first stop- they have a great selection of familiar styles and colors. Only serves North American customers.
18-24mm, $11
http://volksusastore.com/webstores/dollfie/
Volks International
The same selection of styles as Volks USA, but a bit easier to compare.
18-24mm, 1029 yen
http://www.volks.co.jp/en/dollfiedream/eye.html
Parabox
Carries their own line of anime-style acrylic eyes. Very fast shipping, too.
10-22mm, ¥700
http://parabox.jp/eng_new/shopcart/eye_anime_basic.html
Cool Cat
Nice alternative to Volks, cheap shipping is a plus
22mm, $11
http://us.sk-coolcat.com/
Leeke World
A bit pricey for the Glib chara eyes
20mm $12, 22mm $13
http://www.leekeworld.com/En/Product/p_list.asp?B_catalog_num=23&M_catalog_num=40
The Junky Spot
They carry Glib, Hujoo and Parabox eyes in smaller sizes
20mm, $9-11
http://junkyspot.com/obindex.html
Dollfie World
Sells Volks goods at markup, also carries some custom-made eyes
20mm-24mm, $14-18
http://dollfieworld.com/en/23-eyes
Souldoll
Their line of Bling eyes is quite diverse but pricey, watch for annual sales
12-22mm, $22
http://souldoll.com/shop/step0.php?b_code=B20021125011548&c_code=C20080517072522
Pupa Paradise
D Eye Y bases can be used to make your own custom eyes
10-24mm, $1.80
http://pupapa.com/index.php/en/
SQ Lab
Carries their own line of resin eyes. Sometimes slow to answer emails or ship orders for English speaking customers.
22mm, $15
http://www.sqlabdolls.com/
Ersa Flora
Custom anime eyes, can also manufacture eyes to order. Currently on hiatus
8-22mm, $15
Lizanna
Canada-based creator, formerly operated as Juu-Yuki before abruptly closing. Unfortunately they have once again abruptly abandoned their store, so I can’t recommend ordering from them.