“Cyclopia is a rare birth defect that occurs when the front part of the brain doesn’t cleave into right and left hemispheres. The most obvious symptom of cyclopia is a single eye or a partially divided eye. In humans, cyclopia affects an average of one in every 100,000 births, the study authors reported. It means the forebrain of the embryo doesn’t form two equal hemispheres. The forebrain is supposed to contain both cerebral hemispheres, the thalamus (its chief function is processing information going to and from the spinal cord and cerebrum. It also regulates sleep cycles, consciousness, and alertness. It sends information and processes the information from the brain to areas of the body including bodily functions.) and the hypothalamus (plays a crucial role in many important functions, including: releasing hormones, regulating body temperature, maintaining daily physiological cycles, controlling appetite, managing of sexual behavior and regulating emotional responses).In all species, those born with these severe defects typically don’t survive for long — the researchers of the 2015 study described the condition as “incompatible with life.  Survival is death in embryo or one day after born for most cases.”

Life Science (lifescience.com)