People suffering from winter Seasonal Affective Disorder may experience low mood, increased sleepiness, social withdrawal, and a craving for high starch foods. 

The study published in the Open Access Journal of Behavioural Science & Psychology gave questionnaires to a sample size of 175 student participants to understand the extent of mood variations due to changing seasons. The questions helped researchers estimate the deviations in person's sleep, energy levels, weight, and appetite in fall and winter months.

Dark-Colored Eyes Vs. Light-Colored Eyes

"We found that people with light or blue eyes scored significantly lower on the seasonal pattern assessment questionnaire than those with dark or brown eyes," wrote Lance Workman, the lead author of the study and visiting professor of psychology at the University of South Wales.

Workman further said that the findings of the study resonate previous research concluding that people with dark-colored eyes are more vulnerable to depression than the ones with light blue eyes because of the difference in how much light their eyes can process. 

Melatonin And Social Withdrawal

The author explains that people with light-colored eyes, or gray/blue eyes, are more sensitive to light. It means that they do not need as much light for their retinal cells to process visual images. This also indicates that these people do not release as much melatonin as the dark-eyed people during the winter season. 

Researchers revealed that melatonin and its production can aggravate symptoms of depression in colder months. As a result, people with light-colored eyes are more resilient to SAD. However, that is not to say that people with blue eyes don't suffer from SAD-induced depression, according to Workman. 

Melatonin is a sleep hormone that helps the body to power down. However, researchers believe that imbalanced hormones such as melatonin and serotonin, a mood-stimulating hormone, can make people feel lethargic and sleepy during the fall and winter. 

He adds that eye color is not the only factor that can lead to SAD. People who spend too much time indoors are also exposed to the risks of SAD and winter blues. Luckily, people struggling with seasonal depression can overcome its symptoms and improve their mood by simply going for a walk, especially when it is sunny, Workman adds.