"Typhl-" is a prefix that is commonly used to indicate a lack or absence of sight. However, there are several synonymous prefixes that can be used interchangeably in place of "typhl-". These include "an-" which means without or not, "a-" which means absence or lack of, "amauro-" which means blindness or dimness, "nyct-" which means relating to night or darkness, and "hemeral-" which means relating to day or light. All of these prefixes can be used to describe various degrees of blindness or impaired vision. It is important to note, however, that the specific use of these prefixes may vary depending on the context in which they are being used.