Before anyone gets worried or concerned, this was just based off of a thought. And rather than bottle it up to worry about nothing later, I decided to vent it here. It's not meant to be a well crafted piece- it was a stream of consciousness.
~
"I'm at the hospital now." the rabbit said into the phone wedged between his cheek and his shoulder, his hands clutching the steering wheel of his car. The past forty-five minutes had been a blur yet the beginning and the present were still in complete focus. He grumbled to himself as he grabbed the next available ticket for the parking garage. Every additional moment seemed like it dragged on as he hastily sought out a parking space...
'Mom @ hospital' was what the message on his cell phone read. He was at school at the time, in between classes when his phone fatefully fluttered in his pocket. His eyes dragged over those words, slowly at first then more fervently as the weight of it sunk in. He didn't hear his friends ask if he was okay. He didn't feel their hands on his shoulders to snap him from his reverie, though they could feel him start to shake. Turning his head to his closest friend, he spoke in a strained voice, eyes wide and sunken in that moment of creeping terror, "I have to go." He could see the question forming in his friend's mind, the rabbit gearing himself to be rude. Instead, he heard the lizard quietly say, "Ok... go." 
---
The words being spoken to him registered... but he was still in shock from the suddenness of it all. It was a stroke, hemorrhagic. It must have started as a headache and she had taken a painkiller that also thinned her blood. By then, there was little they could do. The rabbit merely sat there, eyes open yet his gaze directionless.
"Do you understand?" the doctor said, the pause from the explanation bringing the rabbit back into focus. Those big, blue eyes turned up to the white-coated professional, trying to keep his voice level as the tears welled and his lips quavered. As much as the doctor tried to appear stone-faced there was the flicker of emotion that whisked across the marmoset's features. "She went quickly... and without pain. Well... minus the headache, of course." he replied, punctuating it with a bite of humorless laughter. The doctor's mouth hardened into a line before he nodded. "What happens now?" the rabbit asked after another pause. "Now... " the doctor said, handing the rabbit his mother's wallet- her face affixed to the little plastic card that was her license out front in its own little pocket. The doctor slid the license from its holster, turning it over to show the signature beside 'organ donor'. "She's about to help a lot of people."
---
There were a lot of people who were helped, but the story that affected this man the most was of a young family who had been affected by a terrible accident. Without going into grisly specifics, a young bear cub had been rendered blind. And his mother's eyes were to be donated to him to help restore his sight.
The rabbit knew he had no place to intrude, especially on a family being thrown from one emotional extreme to the other. But he did leave a letter with the nurse, instructing them to give it to the parents. 
"I need you to realize something. My mother never met you. She never knew you, saw you, or even heard about you. Yet she was willing to give you a  piece of her so that your life could be better."
---
It was years later by this point, the rabbit returning home after another day at work. He was sore, tired, and wanted to go to sleep. He was about to rush in and hit the bed when he noticed a  letter had been slipped into his mailbox.
Inside was a picture of a beaming brown bear with familiar blue eyes and a few letters. One was from the parents, expressing their gratitude and thanks for such a gift. It went into detail how they were trying to raise their son to try and be at least half as caring and thoughtful as his mother had. The other, in crayon, was from the cub himself thanking for those eyes- explaining how he liked video games and coloring and watching cartoons.
The rabbit's throat tightened as the tears just began to fall, running down his cheeks and tracing his jawbone until the tears beaded at the tip of his chin before dropping to the floor.