Aspherical adjustable diopters
During this assignment we developed an adjustable lens to correct an eye abnormality called astigmatism. The lens of people with this condition is rugby ball shaped and therefore has to be corrected with an asymmetrical lens in the shape of a cylinder. The correction has to be made at a certain angle which is different for each eye and every person.
Based on the liquid filled adjustable glasses developed by Joshua Silver we wanted to make an adjustable lens that in the future could be used in third world countries.
The curvature of the lens had to be adjustable, therefore we designed a contour shape of a lens that is stiff in the X-direction by can bend in the Y-direction.
After several prototypes we created a 3d printed lens of which the curvature could be adjusted using two screws. We filled the lens with glycerol since it has a refractive index, similar to glass and specialized plastics used in optics.
While making use of a grid we were able to measure the x and y distortion to calculate the correction of the lens.
Later on we developed a system with seven parallel lazer beams which we could shine through the lens to find the focal point. We made a mount to house and adjust the laser diodes to make them perfectly parallel.
After doing extensive testing we noticed that the surface of our lens wasn't completely cylindrical but rather bell curve shaped.
We treated our lens with a matte primer and 3d scanned the lens surface. To visualize the curvature of the lens we use a false color method.
