The incident was recorded in the BMJ Case Reports, and describes a woman who was 35-weeks pregnant moving into arguably the tamest of yoga positions - downward dog.
The report says she experienced a 'sudden onset painless loss of vision and a large floater in her left eye while doing yoga.'
She had, in fact, experienced valsalva haemorrhagic retinopathy - a bleed inside her eye affecting her retina.
It's believed that the strain involved in getting her head lower than her bottom while heavily pregnant caused the sudden bleed.
Thankfully she went on to have a problem-free birth, and 5 months after her blindness was diagnosed the condition had cleared and her vision had returned.
While yoga is considered generally a safe exercise for pregnant women to undertake, however there are certain positions that are not ideal for a pregnant body as they can cut off blood flow to the baby or result in abdominal strain. Be sure to let your yoga teacher know if you are pregnant, and ask how to approach each pose safely.
This article first published on New Idea.