What is a synonym of the word design that can be used in context of evolution?
Although not ideal, "adaptation" is more appropriate than "design" as a noun describing something that has come about in an evolutionary context, even though not all evolution is adaptive.

In writing, though, I would not phrase it as you have, rather I would change the agency from something evolution does as some sort of "entity" which makes it sound like a goal-driven "designer" with whatever words you use, and instead say that "Eyes evolved from simpler photosensitive groups of cells." Eyes deserve the agency, because having eyes is what would improve the survival of an organism versus eyeless conspecifics and increase the proportion of eyed individuals in the next generation (I hope my simplification of the eye-evolving process as if eyes are a simple Mendelian trait isn't too distracting here, I mean it mostly as metaphor), rather than eyes being a "goal" of something called evolution.

Similarly, you would not say "Chemistry makes water from hydrogen and oxygen," rather you would say something like "Hydrogen gas reacts exothermically in the presence of oxygen gas to produce water." There is no agent "chemistry," that is just the word we use to describe the set of processes in the universe that govern how molecules/atoms/subatomic particles interact. Similarly, "evolution" is not an agent who does things.

One place I would differ in this guidance is in talking very big picture, such as saying that "evolution produced the wide variety of species present today"; in that example, there isn't anything more local to act as an agent, and it's appropriate to refer to the evolutionary process as a whole.