The main risk for a detached retina is head impact, not necessarily eye impact. Although, yes, you want to avoid getting punched, kicked, or poked in the eyes.
Although it does put an emphasis on falling safely and gently, Aikido still results in high impact forces hitting the ground. This is especially true with a technique like irimi nage which requires a back breakfall.
Obviously this rules out Judo as well.
Ground grappling arts like Brazilian Jiujitsu use the head like a 5th appendage, subject to sometimes high impact forces including accidental strikes as your opponent is struggling against you.
Taekwondo generally practices without any head contact whatsoever. They often just "show" kicks and punches to the head. But there's still a risk of accidental strikes. Even wearing whole head padded sparring gear won't prevent sudden impact forces.
Wing Chun also doesn't do a lot of contact to the head in practice anyway. They sometimes spar, and that's where you have to exercise caution. You tell your sparring partner to only "show" to the face, no contact there. And no throws.
You could look into escrima / kali. So long as you're doing stickfighting, there's almost no head contact, except for accidental strikes. Since the sticks don't carry much mass, a stray hit to the head with a stick probably won't result in high impact force. But you would need to wear safety goggles to prevent getting a stick in your eye by accident.
You might try other weapons styles besides escrima, such as kendo, iaido, and fencing. These don't generally result in any head impact. Kendo has full, solid head gear that takes most of the impact really well. Fencing has no mass behind it, making it unlikely anything could affect your retina (but wear safety goggles). Iaido is completely non-contact.
And lastly, there's always non-contact / performance-based martial arts. For example, Contemporary Wushu Kung-fu. Wushu is very challenging, requiring a high level of refinement over time. It's also very cool to look at and to do. Just watch out for the g-forces as your spin your head around. And make sure you don't fall from a botched air technique such as the butterfly-twist or an aerial.
You can try traditional forms of kung-fu that don't do sparring, also. You'll have to look around where you are to figure out who does what.
Ultimately there's going to be risk in anything you decide to do. Even if you decided to do a sport like Tennis. There's still a risk. You just have to be mindful of what you're doing and prevent / avoid anything that might cause problems.
Another thing to consider is retina surgery. From what I gather, this involves shining a laser at your retina, and it kind of welds your loose or detached retina to your eyeball. It's done when your retina detaches or tears. But I speculate (I don't know) that they might also do it as a preventative measure. It's something to discuss with your doctor. And definitely get a second opinion if you're considering surgery.
At the very least, it's good to know that a detached retina usually can be fixed with surgery, if it happens to you. You just have to make sure you see your doctor immediately if anything changes about your vision, even a little change.
Hope that helps.
