Many of the Jews of Jesus's time believed that if a person was blind or deaf or crippled, it was because he or his parents or someone in his family had sinned. This was not the teaching of the law of Moses. (See: [[rc://en/tw/dict/bible/kt/sin]] and [[rc://en/tw/dict/bible/kt/lawofmoses]])
The Bible often speaks of unrighteous people, people who do not do what pleases God, as if they were walking around in darkness. It speaks of light as if it were what enables those sinful people to become righteous, to understand what they are doing wrong and begin to obey God. (See: [[rc://en/tw/dict/bible/kt/righteous]])
Jesus calls the Pharisees blind because they see that Jesus is able to heal blind people but they still do not believe that God sent him ([John 9:39-40](./39.md)). (See: [[rc://en/ta/man/translate/figs-metaphor]])
Jesus refers to himself as the "Son of Man" in this chapter ([John 9:35](../../jhn/09/35.md)). Your language may not allow people to speak of themselves as if they were speaking about someone else. (See: [[rc://en/tw/dict/bible/kt/sonofman]] and [[rc://en/ta/man/translate/figs-123person]])