I have attached the current logo for Keratoconus Australia that we are trying to update.
The graphic element that looks like an egg is representitive of the eye desease which causes the cornea to extend in a cone shape.
The design element shows the heathy eye on one side and the elongated cornea on the other and has been used as a way to simply illustrate the disease.
It would be good if you can include a graphic representation of the disease somewhere, but this is not mandatory.
You should do some study on the disease first, looking at the google image results for "Keratoconus" should be enough to work out what's going on.
The disease onsets at puberty so while this is not a "youth" brand some appeal to the teenage market should be considered, keeping in mind that it's still an eye disease and can't be made "cool"
People with low vision are the target of market, so bold, high contrast and avoid fine detail in the graphics or really narrow fonts, I would suggest 2 colours maximum and avoiding subtle gradients.
The letters KA (Keratoconus Australia) can be used as an element in the graphic, but the full title should appear in the logo as well. The design will be used "stacked" as well as "leaderboard" depending on the use case.
That's it, good luck.