When your past 50 and your eyes cannot adjust to darkness and close up vision so well - do not be tempted to use a Stanley knife blade without a suitable holder.
Using the blade the wrong way round will, without doubt, result in injury and much blood, especially if what you were trying to cut was quite tough.
One final point to note, brake cleaner will not remove dried blood but will sting when you get it in the wound.
Owwww 
I’m wincing just thinking about it!!
Ouch indeed!!
should have gone to Specsavers!
Best not to work on your own eyes, particularly with those tools As Mr Bean says, see an optition or get someone to point one out for you 
This is one lesson I would not want to have learned myself.
Dremmel baby