If your parent has trouble putting in his eyedrops because his hands shake a bit, have him place a one-pound wrist weight on his wrist. The extra weight can help cut down on the shaking. If you think he's not strong enough to safely handle the weight, another option is for him to approach his eye from the side rather than the front, resting his hand on his face to steady it.
He can also get a device that helps self-administer eyedrops; talk with your parent's eye doctor or pharmacist.
