Generally, under the due process clause, the defense has a right to introduce eyewitness testimony in a prosecution, provided that the eyewitness is available for cross-examination. There might be evidence that bears on the reliability of the eyewitness testimony (what is dark or what is light), but this bears on the weight the jury should give the testimony and not its admissibility,
In the famous Almanac case, President Lincoln represented a defendant charged with assault. A key prosecution witness testified that he saw the assault under the light given off by a three-quarters moon. Lincoln produced an almanac to show that the moon was about to set on the day of the purported identification, thereby discrediting the prosecution witness's testimony. Lincoln won an acquittal.
