People who suffer from anorexia may be at a higher risk of developing eye damage, according to a study published in the British Journal of Ophthalmology.

Researchers measured the eyes’ electrical activity and the thickness of the macula, which is the part of the eye that processes light and controls central vision, in 13 women with anorexia. The team then compared the results to a control group of 20 female participants.

The results showed that the anorexic patients had developed thinner macula and nerve layers connected to this part of the eye. Also, the team discovered that women with the eating disorder had lower levels of electrical activity, which allows the brain to process images.

Because the team was unable to determine if these problems could lead to blindness, they concluded that future long-term studies will be needed to study how this may affect someone losing their vision. Furthermore, the investigators suggest that other research should monitor if returning to healthy eating habits could fix the damage.

Approximately 8 million people in the U.S. suffer from an eating disorder, according to South Carolina Department of Mental Health.