UK Keratoconus Self-Help and Support Association

This is probably the best simple description of my KC damage from my lens fitter. He specialises in KC and has give lectures at Manchester Uni, in his younger years.

Quote:
"Think of the cornea as a double glazed window. When its good and normal, you can just see through it. Light goes straight through the first pane and the second pane.

Simple KC is where the first pane is damaged and bends the light somewhere else.

Complex KC is where the first/front pane and second/back pane are both damaged. Light gets bent from the first pane, and also get bent again from the back pane.

Simple KC is easy to fix with glasses/contact lenses.

Complex KC is difficult because you can't alter the shape of the back pane. That why I get ghosting with glasses and contacts. I need a beer barrel shaped lens to help redirect through my damaged back pane."

It makes perfect sense to me

Good metaphor.

My children used to call my corneas 'my little windows'. One of the window panes inky study had a flaw and it seemed sensible to them that, in the same way as things looked wonky when viewed through the flawed glass, I saw things look wonky when I looked at them through flawed corneas.