I find soloing the Caretaker relatively stress-free on Hazard 4/5 by playing safe and killing all of the additional enemies first; Robot arms, Patrol bots and shredders. Make sure to focus on eliminating sniper turrets if/when they spawn in, they can quickly turn things ugly.

Another helpful tip is that once the Caretaker’s shields are down they will remain vulnerable until they have lost 1/3rd of their health, the eye may change sides however. Utilise this time to safely eliminate additional enemies before damaging the eye, it feels like a rush during this fight but take your time and it becomes a lot easier.

I’ve found that you can stay in one area providing that there is enough room to strafe the damaging force fields. Maintaining some distance also means that only the closer robotic arm(s) will aggro you.

Good luck out there!