it's quite a common occurence to see retained eyecaps which is usually down to environmental issues like too dry in the tank / enclosure. Whenever your snake sheds its always a good idea to check the shed to see if both eyes have shed properly this way you can visually confirm whether it has succeeded or not.
I dont like to see people physically try and remove eye caps unless they are very experienced and know what they are doing, which is one of the reasons why any snake keeper should ensure they have appropriate help at hand such as a reptile specialist or vet etc ( even a local breeder) for such problems that may or may not unfold.
Sometimes it may look like they have an eye cap when they infact do not so someone prodding and poking the eye trying to remove something that is not there can cause lasting damage to a snake that simply needs correction in their environment.
I recently got a ball from a workmate who got it for his 12 year old son but they/he decided it was a problem feeder and they were struggling to keep it healthy.
This snake was living in poor conditions ( due to ignorance ) and was a problem feeder due to this on top of that it had about 4 sheds worth of retained eyecaps, I removed these myself under the correct conditions very carefully got him settled ina new enclosure with hides and proper temps and humidity and he is doing great now and eats like a trooper. This is an example of a snake that needed intervention even a good shed did not remove the retained eyecaps otherwise I would not have touched the eye.
I decided to keep him and gave the boy one of my young males I bred a year ago and set up his tank and made sure they knew what they were doing (this was about 2 month ago ) and the wee lad has got his confidence back and thrilled with his new snake.
I am using this example of the many keepers out there that are ignorant to recognising problems or dealing with them, to simply tell anyone having problems with eye caps etc to just remove it etc is not often of benefit to the snake in question.
Always check environment after the 1st bad shed you get as this will most likely be the cause and correcting this will in all likelyhood sort the problem out in the next shed with no need to go poking around the snakes eyes.
Your going to make your own life easier as well as the snakes if you can make the effort to get this right and monitor it.
If you dont know what your doing ( removing eye caps is a delicate thing) its not worth just attempting, take it to the vet if all else fails (2nd shed etc ) or get a breeder / experienced keeper to show you safely.
Laslty no keeper should feel embarressed asking for advice nor should they do something they dont feel comfortable doing, both of which I have seen lead to a snake getting misstreated and in some cases damaged due to botched jobs from people attempting something they are not experienced in doing. You should not need to interfer with the natural process of shedding other than boosting the humidity to assist either before or after imo.
Good regular sheds are a good indicator of healthy set up (Temps and humidity) and a healthy snake that is eating and growing, when this ceases then 9/10 its the set up that has a problem , husbandry is the key to success.
damm I went on a bit sorry people

.......so in short then, let it shed again or put the snake in question into a humid box with a wet towel or cloth the eye cap may just come off, otherwise the 2nd shed ( if proper temps and humidty ) should come off by itself with no need of prodding a delicate eye.