Dual wavelength interferometry application to evaluate shapes for corneas and intraocular lens

Dual Wavelength Interferometry (DWI) is a well-known technique that has been applied to measure rough surfaces and also transparent samples with high resolution. It has aroused great interest in the field of biological research due to its nonintrusive nature, since it does not require contact with the sample and is usually harmless. Holograms recorded with different wavelengths are required. The combination of different wavelength values allows changing the measurement range. Thus, this technique allows to measure the shape object from microscopic to large scale, just selecting the appropriate source wavelengths. In this work, it has been analyzed the feasibility of using DWI to measure the surface of natural and artificial corneas and of intraocular lens (IOL). To adapt the technique to the corneas size, the wavelengths values should be very close that gives a bigger effective wavelength. For IOL surface evaluation microscopic resolution is required. For this recordings, significantly different values of wavelength must be used to get an effective wavelength of few microns, but that will make the chromatic effect non-negligible.