These are eye textures in zipped files. Down them and unzip them. Then you can take the eye textures in world and make your eyes.
In world right click your “body parts” folder in your inventory. Choose “create body part” then “create eyes”. Name the eyes something and then wear them. Then right click your avatar and choose “Edit Appearance” from the pie menu. In the appearance edit window choose the “eyes” tab. Drop the texture that you want into the texture box that shows an eye in the appearance window. Then make sure that you move the last slider all the way to the end so that it’s all the way lightened. Save and you’ve created your eye.