Use staples for the carpet, not nails. Nails will rip out in short order. Also, get a big, honking lag bolt for the scratching post attachment. I used 4 huge 10d framing nails and they still managed to loosen the post after 6 months. Switched to one 3/8" by 4" long lag bolt and it's held up since.
Speaking of blind cats, I got this from the place i adopted one of my cats:
In the midst of record cold temperatures in February, "Arrow," was found wandering and injured near Ballston Mall. After being brought to AWLA by an area resident, it was determined Arrow was blind, with his right eye shrunken and a dilated pupil and lens opacity in his left. The results of his x-rays were shocking. Arrow had at least 20 BB gun rounds or shotgun shell fragments in his head and more than 80 throughout his body.
Currently, Arrow is recovering from surgery and has met with a potential adopter. His painful right eye has been removed and while his left eye remains, the retina is completely detached and has a cataract. In spite of his injuries and sad history, Arrow's most remarkable trait is probably his loving personality. He is a friendly, sweet animal - with a loud purr that could be warming hearts in his new permanent home within the next week.
While shocked by this act of cruelty, our staff and volunteers have been overwhelmed by the outpouring of support from across the country. Our ability to help Arrow and other homeless animals in need is only made possible by the generous support of longtime friends like you.
Each year, AWLA takes in over 900 cats. We provide shelter and care as staff and volunteers work seven days a week to find loving homes for them all. Some of these animals will remain at the shelter for a few days or weeks, while others may stay for as long as a year. Ensuring animal health, happiness and quality of life is our top priority.