EyeLife is one of Lifelines' additional assessments.
This assessment is a collaboration between Lifelines and the UMCG Department of Opthalmology department of gyneacology.
The goal of the assessment is to quantify male fertility in the general population using a questionnaire, semen analyses, and plasma testosterone measurements.

Vesper started in Q3 of 2019 and will run until 400 male participants have finalized the protocol.
Participants between 18-55 years old are invited:

• to fill in a digital questionnaire about their family composition, family planning, and fertility
• to visit the UMCG department of gyneacology for the donation of a blood sample and
• to produce a fresh semen sample that will be analyzed the same morning.

Inclusion criteria were:

• Male
• 18-55 years old

Exclusion criteria were:

• Being vasectomized
• Working nightshifts
• Survivor of childhood cancer