Centre for Sensors, Instruments and Systems Development

Universitat Politècnica de Catalunya

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Speckle reduction in double-pass retinal images using variable-focus lenses

CD6 researchers have published a new method for reducing the Speckel pattern present in the retinal images obtained using the double-pass technique. This method may be useful for the improvement of certain instruments used in the diagnosis of vision diseases. The CD6 research team is Carlos Enrique García-Guerra, Mikel Adaba, Montserrat Arjona and Jaume Pujol.

The article published in the Journal of the European Optical Society (JEOS) can be downloaded at the following link:


Speckle arises in double-pass images when coherent light is scattered by the retina. Since this noise degrades the images that are used to characterize the eye, there is special attention in reducing speckle when working with instruments based on retina reflections. In this work, we present a method for speckle reduction in double-pass retinal images by producing minor periodic variations in the vergence of the beam entering the eye with a variable-focus lens during image recording. Measurements in an artificial and a real eye following the implementation of the method corroborate the speckle reduction.
CD6 Centre for Sensors, Instruments and Systems Development
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