Does Your Outlook on Life Affect Your Eyesight?

It's no coincidence that people who suffer from depression describe themselves as feeling blue. A recent study demonstrates that depression really alters the way people visually see the world; it appears grayer to them than to people who do not have depression. Scientists describe this phenomenon as lower retinal contrast gain. The more depressed the individual, the lower their retinal contrast.

A brief description of how the eye works and how physicians typically diagnose depression will help make sense of these results.

Diagnosing Depression

Clinicians diagnose depression by conducting an evaluation of the patient, collecting information on the patient's family history of depression and their symptoms-when they started, how long they've lasted, and how severe they are. There are numerous structured diagnostic tools available to help physicians diagnose depression, determine the severity, and evaluate the effectiveness of treatment. However, many medical professionals do not use these tools with any regularity. Unfortunately, this can lead to misdiagnosis or under-diagnosis of depression, which, in turn, may result in delayed or improper treatment and increases patients' risk for relapse.

The Eye

The retina is the light sensitive area at the back of the eye. It converts light energy into signals, which it sends to the brain through the optic nerve. This is a very simplistic explanation of how we see. Contrast retinal sensitivity measures our ability to see objects that might not be clearly outlined or don't stand out from the background; for example, a gray object against a white background. Contrast is determined by color and brightness.

Contrast sensitivity tests measure our ability to discern objects with low contrast. This ability tends to decline with age. Based on the results of this study, scientists now suspect it may also be compromised in people who have depression.

In the current study, researchers compared 40 patients with depression to 40 patients who were not depressed. Half of the depressed patients were treated with medication for their depression, the other half were not. The researchers found that both the medicated and un-medicated depressed patients had lower retinal contrast gain than those who weren't depressed.

Why Does Retinal Contrast Matter?

Currently, physicians rely heavily on subjective measures, such as self-reporting of symptoms, to diagnose depression. The researchers hope that retinal contrast will add an objective measurement to their diagnostic tool box, increasing the accuracy and timeliness of diagnosis.


Bubla, Emanuel, Kerna, Elena, Eberta, Dieter, Bachab, Michael, and Tebartz van Elsta, Ludger. "Seeing Gray When Feeling Blue? Depression Can Be Measured in the Eye of the Diseased." Biological Psychiatry. 68 (2) (2010): 205-208. Web. 1 April 2010.


Salleh, Anna. "Visual flip to shed light on depression." Web.  19 January 2010.

"Encyclopedia - Contrast Sensitivity." Web.

"The Retina." Hyperphysics. Web.

Zimmerman M. and Galione J. "Psychiatrists' and Nonpsychiatrist Physicians' Reported Use of the DSM-IV Criteria for Major Depressive Disorder." Journal of Clinical Psychiatry 71 (2010): 235-238. Web. 12 April 2010.