The first type of telescope to be built was the refractor. It uses a lens to bend, or refract, light rays to a focus. Glasswork matured in Europe in the 16th Century and by the end of the century artisans had learned how to grind convex lenses that could magnify an image.
Please choose PRINT from your browser menu. Close Window. Lumps and Bumps on the Outside of the Foot. Written By: Dr. Kirk A. Koepsel, D.P.M. Description. There are a few causes of lumps, bumps or prominence on the outside of the foot. Some of these are just normal anatomy; others are due to abnormal processes. Starting from the fifth toe and working back to the heel: A common prominence on the fifth toe is due to the formation of a hammertoe.
This condition can also cause bumps on the bottom of the foot, which look similar to bubbles. Blisters are a result of too much friction on the foot, often caused by tightly fitting or new shoes, which cause the outer layers of skin to rub against each other, separates, and proceed to fill with liquid.