Orthokeratology has the benefit for slowing down myopia progression and enabling unaided vision during the day. To investigate proposed possible changes of conventional and multifocal orthokeratology in the cornea and choroid this study will image both structures with high resolution optical coherence tomographs over a six month period. Findings will help to plan larger trials over a longer period of time in adults and teenagers.

Inclusion Criteria:

• Men and women aged over 18 years
• Myopia defined as between -1D and -6 D with an increase of 0.5D within the last 18months prior to inclusion
• Prospect orthokeratology contact lens wearers
• Normal findings in the slit lamp examination, no corneal pathologies

Exclusion Criteria:

• Participation in a clinical trial in the previous 3 weeks
• Presence of any abnormalities (such as refractive surgery) preventing reliable measurements as judged by the investigator
• Current contact lens wearers
• Pregnancy, planned pregnancy or lactating

10 healthy volunteers