The exact causes of dyslexia are still not completely clear, but anatomical and brain imagery studies show differences in the way the brain of a person with dyslexia develops and functions. It is also shown to be genetics. If you have it, there is a good chance your parents or grandparents had it. Many go through all their lives without being diagnosed. I was in university before my dyslexia was caught. I had developed many tools and tricks to help me on my own without knowing that I had a learning disability.
Moreover, most people with dyslexia have been found to have problems with identifying the separate speech sounds within a word and/or learning how letters represent those sounds, a key factor in their reading difficulties. We mix letters and/or numbers. In my case, it’s both. If two words are spelt almost the same, I have a lot of difficulties telling them apart.
Dyslexia is not due to either lack of intelligence or desire to learn; with appropriate teaching methods, students with dyslexia can learn successfully. I have a university degree and a good career in computer sciences. Dyslexia doesn’t have to put limits in your ability to achieve your dreams.