Quality of Life... who defines it?

I recently read an article about a young girl who has been denied a kidney transplant due to her developmental delays, mental retardation, mental impairments... whatever phrase you choose.  The family is furious, as they should be.

I am a bit confused by how we as a society define quality of life.  How is it determined? Who defines quality of life? Do they have a set scale?  Do they have specific criteria?  Do they have family members or children who have similar conditions that assist them in determining and defining quality of life?

When Cienna was diagnosed with retinoblastoma, I can recall the argument about giving her chemotherapy to save her vision like it was yesterday.  We were in a different position than most families receiving a new retinoblastoma diagnosis. We already lived with a child who had the equivalent of a traumatic brain injury who was also visually impaired.  He would never be able to walk or speak.  He also had seizures and other health problems.  Cienna had a fully functioning brain only her eyes were affected.  To me vision was the least of my concerns.  People can live functioning lives without their vision.  I've met blind people who have had jobs and families.  Cienna's future quality of life was predicted to be less if she was unable to see.  This was predetermined... not by us.

F's life is judged or defined as less, less joyful, less healthy, less independent, less smart... the list goes on and on.  I've seen the look from people who feel sorry for him.  I see how people judge him and form opinions about him. I can tell you, I'm sure, they only see what he unable to do. We've made decisions for F at times throughout his life to maintain or improve his quality of life that were hard to make.  Decisions that came with risks, but the benefit outweighed them. F is an adult now.  He's very in tune with his health needs.  He knows how he feels and when he needs medical attention.  He is involved in his own care.

F is a joyful young man.  He has a life he enjoys.  His independence is defined by him and it's different than what independence means to others. He controls what he can. He has a great nurse who assists him.  He is teachable and has a thirst for knowledge and learning.  Should he become ill or need medical care the power of defining his quality of life could possibly be placed in someone else's hands.  Shouldn't decisions be up to  F and his family?

It saddens me deeply to hear about individuals or groups that have the power to determine or define the quality of a life that they have no understanding of.  They see this life as being "less" because it's different than what is predetermined as the norm.