Page 50 of the book
Gustav Karpeles: A Sketch of Jewish History. Translated from the German [by an anonymous translator]. The Jewish Publication Society of America. 1897.
contains the following interesting though unsourced boast:
"A Jew was the first to study the refraction of light ; a Jew introduced to Europe the famous work of Dioscorides, the foundation of the whole science of botany ; a Jew wrote the first textbook of geometry in Europe [...]" ${}\hspace{24.76em}$(B)
For a historical research project, I need to know:
Question. Which three Jews did Karpeles refer to in (B)?
(I am mostly interested in the first and the last of the three contributions alleged, whence my headline for this question.)
Remarks.
I made considerable efforts of looking through reference works and online sources, but in none of the three separate domains (1) light refration, (2) Dioscorides' writings, (3) geometry textbooks, did I find references to significant Jewish involvement in the early stages. (Except perhaps in the case of Karpeler's least interesting claim, the one about Dioscorides: it is well known that there were many Arab and Jewish translators of Greek scientific texts around the Mediterranean, from islamized Spain all the way to Greece, and one of those translators probably was on Karpeler's mind.) What I am interested in for the most part are (1) and (3). In the case of (1), Alhazen, of course, is being mentioned a lot as an early contributor to the study of light, but as far as I know, Alhazen was not Jewish, not even secretly so. In the case of (1) and (3) I still have no inkling of whom Karpeler is referring to.
As already mentioned, Karpeler's book does not contain any sources or references, not even for any other statement in the short book; this has a systematic reason: in the foreword, the book is said to be a translation of stenographic notes of a lecture given by Karpeler in the winter of 1895/1896 in a B'nai B'rith lodge in Berlin; as such, it is not meant to be a carefully referenced work, but rather has some degree of pep-talk-flavor mixed to it; still, Karpeler's three claims stand and call for an explanation. (If Karpeler's claims turn out to be untenable, there still remains the minor sub-question of whether Karpeler's statements were made from whole cloth, or whether he mixed up some names and e.g. thought of Alhazen as a Jew.)