Published September 29, 2026 by Amanda Hays.

University of Washington (UW) experimenter Mark Walton has spent nearly three decades and millions of taxpayer dollars tormenting monkeys, including experimenting on baby monkeys who were forced to wear goggles for the first three months of their lives or had tendons in their eyes severed for vision experiments—not to advance science, but just to keep his job.   

Experimenters traumatize baby monkeys by ripping them from their mothers and strapping goggles on their faces for the first few months of their lives to permanently distort their vision in cruel and useless experiments. For illustrative purposes only.

You don’t have to take our word for it. He said so himself in documents just obtained by PETA.

By Walton’s own admission, “I have to publish papers to stay funded, and there is the risk of my lab space getting [taken] away if I never run experiments.”

So he keeps the experiments running, papers publishing, and monkeys suffering.

Slicing Baby Monkeys’ Eyes

Walton’s vision experiments on baby monkeys are his magnum opus of cruelty.

Experimenters begin by stealing days-old monkeys from their mothers. Some babies then have the tendons in their eyes sliced, while others are forced to wear vision-distorting goggles for the first three months of their lives.

Once the monkeys are older, Walton’s laboratory slices open their skulls, installs invasive recording chambers, and inserts metal coils inside their eyes. They strap the monkeys into chairs and use the metal post that is screwed to their skull to keep them from moving.

The monkeys then endure repetitive and wasteful experiments, all so Walton can record their eye movements and brain activity. He places the restrained monkeys in a room without any light and shines a laser dot on a screen and “rewards” the monkeys with drops of applesauce if they look at it.

If you’re thinking that sounds more like a demented carnival game than a hard-hitting scientific investigation, you’d be right.

Pushed to the Brink

UW robs baby monkeys of every comfort, developmental skill, and pivotal family bond by taking them from their mothers. It’s no wonder they go mad.

Documents PETA obtained show monkeys in Walton’s laboratory exhibit clear signs of stress, anxiety, and an extraordinary pattern of self-mutilation.

Two monkeys, Sonic and Goose, bit themselves so severely that Walton was forced to take note. He did so not out of consideration for their well-being, but from concern that their excessive self-mutilation would “threaten their usability” in his experiments. 

Walton went further in his lab meeting notes, suggesting that conditions at the primate center itself might be contributing to the problem: “… [self-biting] implies that there is something going wrong here at the primate center that is making this more likely to happen.”

Rather than concluding that the monkeys should be removed from the experiments, Walton sought permission to continue subjecting Sonic, Goose, and other monkeys to brain scans, invasive surgeries, eye-coil implants, restraint, and useless experiments.

What You Can Do

Walton is one of many UW experimenters PETA has exposed for turning monkey torment into long, cushy careers.  

The Washington National Primate Research Center is riddled with them. They rake in millions in federal dollars to subject animals to deadly tests, while failing to produce human-relevant results. Please TAKE ACTION to shut it down: