Contrast sensitivity is a tool use to evaluate the visual function in all patients. It can be modified by different pathologies or by age. The purpose of this study is to identify the changes that could be in relationship with the course of diabetic retinopathy comparing with diabetic patient without retinopathy and in patients with diabetic macular edema so if it is a difference, research for therapeutic strategies to improve it in this patients.

Contrast sensitivity is defined as a subjective measurement, it is the ability to separate the image between figure and background, taking into account the minimum amount of light required; it is evaluated by the contrast threshold, which is the smallest amount of contrast needed to be able to see a target and solve their characteristics, would be his reciprocal value. Medina et al. curve reported in healthy Mexicans SC 5 to 80, where > 51 years have decreased compared to contrast sensitivity studies international; further that contrast sensitivity in older groups of 41 years is decreased high frequency.

Inclusion Criteria:

• DIABETIC PATIENTS
• 40-60 YEARS OLD
• ANY GENDER
• VISUAL ACUITY >0.25 IN DECIMAL EQUIVALENT,

Exclusion Criteria:

• PATIENTS WITH CATARACTS OR OTHER MACULOPATHY
• PATIENTS WITH CONTACT LENSES
• PATIENTS WITH REFRACTIVE ERROR >6.00DP
• PATIENTS WITH PREVIOUS OCULAR SURGERY

Diabetic patients attended at Ophthalmology service in a general hospital