What Day is referring to is his life at the beginning, when he discovered that he would go blind and that his injury could be treated with a transplant. At that moment, Day felt like his life was over, so he locked himself in his room, frustrated and depressed, waiting for surgery. He forgot to live for that entire year, he became a statue like Mee, and he was willing to fade away and to make himself invisible to the eyes of the world until his current situation could change at some point. It was one of the hardest and loneliest moments of his life. Until Mhok arrived and showed him that life went on and that there were many things he could do. Day went out into the world again, interacted with his friends again, began to make plans, participated in activities, traveled, danced, had fun, fell in love, made love for the first time... He realized then that he could live his life in the same way as others. As he accepted his new reality, Day regained his will to live and enjoyed himself again. He fought for his independence, finished his degree, opened his own bookstore, gave talks at the association, wrote a book... Day had a full and happy life, one in which he developed professionally, one in which he felt fulfilled, one in which he proved to the world and to himself that he could handle himself. If you look at the scenes of Day when he regained his sight, you can see him doing what he had already done when he was blind: he participated in a marathon again, he hung out with his friends, he went on dates with Mhok... his life was still the same, because his life was already normal before he regained his sight.
Therefore, Day talks about the difficulties and painful moments he faced throughout the process, but in the end, when he managed to accept his reality and adapted to it, he began to see the light and he started living his life. He no longer wanted to be locked in his little corner, he wanted to be part of the world.

It surprises me that people say that Day's words imply that to be normal is to be able to see... Hasn't Day repeated ad nauseam that he didn't want anyone to pity him? Hasn't he said time and time again that he doesn't want to be treated or seen differently simply because he can't see? Hasn't Day shown his displeasure with the fact that others might think he can't take care of himself? Because he is a normal person and wants to be treated as such. Have you forgotten all this?
How can you say that this series is ableist when it shows the opposite? They have strived to teach us during 12 episodes that people with disabilities can have autonomous, full and happy lives. We see it through Aon and we see it through Day. Let's not forget that everything Day achieved, he achieved while he was blind. Day was already happy before he regained his sight, so his current happiness does not depend solely on being able to see.

The series is not telling us at any point that disability must be cured to be happy. Day has an injury for which there is treatment. They tell us from minute one, and from minute one, he is on the waiting list. Day was not born blind nor does he have a permanent disability. My question is: would you say to those people who have the same injury as Day and who have also decided to have surgery that both their choice and their own experience are not valid? Would you tell them that everything they have experienced and learned as blind people does not count for anything because in the end they have recovered their vision? Is there only one valid experience in the world? Is there only one reality and only one representation? Isn't that a bit discriminatory? Would you say to those people: don't have surgery, it is better that you remain blind, so everything you have previously experienced will not have been in vain? Would you tell them: yes, I prefer that you not regain your sight, so you will be a more inspiring person to me? Would you make all these people feel bad because they have a treatment option while many other people in the world don't?
Because then, if you are not able to empathize with a fictional character, you will not be able to empathize with a real person either. Everyone has the right to decide about their own life and their own body. Everyone has the right to choose what makes them happiest. Day should not be judged for wanting to regain his sight. Day shouldn't be judged for feeling like it adds a little more happiness to the happy life he already had when he couldn't see. Day was happy when he couldn't see and Day is still happy now that he can see, that hasn't changed. Because his happiness is mainly due to everything he has managed to do for himself, everything he has achieved in life, everything he has learned and all the people around him. Because what is essential, what is important, is invisible to the eyes.

Day's blindness not only changed his life, it also changed the lives of Mhok, Night and Porjai. They would not be where they are now nor would they be the same people they are today, if it were not for this entire process. Day regaining his sight doesn't change any of this. The result is the same. For that same reason, the series does not develop Day's life much further after regaining his sight, because it is not going to change anything that they have already shown previously.
This series shows us different realities and different possibilities, and teaches us that they are all equally valid. Last Twilight is a song to resilience, to the ability to adapt to new circumstances and situations. It teaches us that, although we cannot always change our reality, we can change the way we face it. Day is an inspiring character, a clear example of struggle and improvement and that does not change, regardless of the ending. So I encourage you to watch the series again from the beginning and, this time, reflect on what they are showing you. It is very unfair that a series is brought down simply because people have not understood the message.