Jason asked: “What about drugs-usage? Don’t some drugs ‘contract’ the pupils? Or, would you not be able to say for sure what the normal pupil size was in the first place – so you can’t say if the pupil is contracted or dilated? But perhaps in case of OD, the pupils remain abnormally sized? Or, do they revert back to normal even several hours after one is deceased?
Also, can you see diseases within the eyes? I thought liver-chirrosis colors your eyes yellowish?”
“Yellow eyes”, is marked discoloration of the sclera. It is called scleral icterus, which is suggestive of bilirubin build-up in the bloodstream. In medical-legal death investigation, it alerts to the potential of hepatitis, cirrhosis, liver failure, liver cancer and other medical issues.
Yes, a multitude of recreational drugs of abuse and prescription medications will cause pupils to dilate (larger). Opiates and alcohol tend to constrict (smaller). But, because of the many potential influences and factors that can result in either pupil constriction or dilation, the appearance plays no particular role in contributing to the medical opinion regarding cause and manner of death. Toxicological analysis is the gold standard for objective data.
No, pupils do not “revert back to normal even several hours after one is deceased”. But, there are a quite a number of changes that occur post-mortem. Pupils often dilate due to muscular relaxation, however, one or both pupils may subsequently constrict due muscular stiffening from rigor mortis. It stands to reason that fluid evaporation will also alter the eye/pupil appearance, as would trauma or even post-mortem palpation of the eye.
Another important post-mortem change (not visible), is potassium levels in the vitreous fluid. Vitreous is an interesting topic; I will find some time to discuss vitreous in greater detail. Best regards, -Hal