On my freebiehunts I noticed there are some free eyes but not that many and not always that nice.
I downloaded these from OpenSim Creations. The textures were made by Mistletoe.The creator meant these eyes to be free and they may not be sold in any form.
I placed a box with all 20 pairs here:
Elvensong freebee wall
The eyes are mod/ copy. If you think they are too bright open appearance/ edit outfit/ bodyparts/
click the eyes and use the slider on eye lightness.