Dyslexia is a lifelong disability, but modern advancement has given us training, equipment and array of therapies to handle it. First, you need to know that dyslexic people are not worthless or lesser than others; they just face challenges in writing and reading, but they can be talented in other things like art or math. Improvement is possible with some training and encouragement, which means a dyslexic adult can write and read better.
You need to get to know the dyslexic person to identify what can work for them, bearing in mind that what works for one does not necessarily work for another.
Dyslexic people need help with their feeling of rejection since they may get treated as less than others; neighbors, peers and even family members may insult their intelligence causing them to feel rejection, isolation and low self- esteem.
They need to be treated with compassion and respect; treat their needs as normal and with patience. Make them believe they have the talent to achieve success. Point out to them dyslexic role models who are leaders in the business world and they are many.
Meeting other people with dyslexia is very helpful to feel less alone, they can support each other and swap strategies; you can look for gatherings on social media in addition to support groups.
Make them believe they are hard workers and it is OK to make mistakes as long as they put forth good effort. Building phonetic decoding skills is very important to improve writing and reading skills for a dyslexic person; to break the word into its basic sounds and then put these sounds together to produce the word and the same for the other words. This strategy will help gradually the dyslexic adult to read at a higher speed.