After drawing criticism from many, including comedian Ricky Gervais and the British Union for the Abolition of Vivisection (BUAV), Cardiff University is speaking out on an experiment that involved sewing kittens' eyes shut in order to replicate lazy-eye syndrome. That research was funded by the Medical Research Council.

The study, first brought to light by Wales on Sunday, involved depriving 31 cats of their senses to different degrees. One group was kept in total darkness from birth to as long as 12 weeks while a second group only had surgery later in which one of their eyes was sewn shut for up to a week. The cats' brains were then examined while the cats were under anesthetic in order to record how they reacted to different visual stimuli. Afterwards, they were euthanized and portions of their brains were removed for further study.

Experiments at Cardiff University on kittens have drawn the ire of a variety of groups. Wikimedia Commons.

The university said the experiment, the results of which were published in the European Journal of Neuroscience, was necessary to see exactly how the brain and vision are related and will help researchers treat human children with lazy-eye syndrome, a condition that two to four percent of kids are afflicted with and that can lead to partial blindness, according to pet website Pawnation.

"The condition can be treated in young children of up to about eight years by such measures as the wearing of eye patches," the university said to the Huffington Post UK. “However, in older children and adults, as the brain increasingly prefers images from one eye, the condition is not curable." The university added, "The aim of the Cardiff University study is to better understand this critical period in early life when the visual cortex in the brain adapts to the signals coming from the eye."

Michelle Thew, chief executive of BUAV, saw things in a different light, stating early this week on the BUAV website:

"We know the public will be shocked to learn of this publicly funded research at Cardiff University in which kittens were subjected to unpleasant procedures such as depriving them of light or having one eyelid sewn shut before invasive brain surgery and death. This is unacceptable cruel research."