Why caps stick in the first place
A snake's eye has no eyelid; instead it is covered by a clear scale called the spectacle, or eye cap, which sheds along with the rest of the skin. When a shed goes badly, the body skin may come away while one or both caps stay behind. The causes are usually environmental and fixable: humidity that ran too low through the shed cycle, mild dehydration, rough surfaces missing for the snake to rub against, or occasionally mites irritating the skin around the eye. You can recognise a retained cap after the rest of the shed completes — the eye looks dull instead of bright, with a wrinkled, dented or slightly crinkled surface, and the snake may rub its face along branches and decor trying to shift it. Identify it correctly first: a snake about to shed has cloudy eyes too, and interfering mid-cycle helps nothing.
Safe home help, step by step
Work on the conditions, not on the eye. Raise the enclosure humidity to the top of your species' normal range and keep it there. Offer a soak in shallow, warm — never hot — water for twenty to thirty minutes, supervised, then let the snake crawl through a damp pillowcase or a rough damp towel, in and out repeatedly; the soft friction of wet fabric against the spectacle is what loosens the cap, and the snake controls the pressure itself. Repeat the soak and the pillowcase session daily for a few days. Very often the cap lifts within that window, and if it does not, a cap in an otherwise bright, comfortable snake frequently releases with the next shed once humidity stays corrected — which is a legitimate outcome, not a failure, provided you keep watching it.
The things never to try
Do not peel the cap with fingernails. Do not press sticky tape to the eye and pull. Do not work at the edge with tweezers, and do not force oils or creams under the spectacle. The living surface of the eye lies immediately beneath that scale, and the margin between lifting a dead cap and tearing the eye itself is measured in nothing at all — keepers blind snakes every year with confident fingers. If a technique involves touching the eye with anything harder than damp fabric, it is not a home technique. The same restraint applies to retained shed elsewhere on the body: soak and fabric, never pulling.
When it becomes a vet job, plainly
Book the vet if a cap is still in place after the snake has gone through another complete shed, because layers can stack and harden. Go sooner if the eye looks swollen, bulging, weeping or cloudy in a way that deepens rather than clears, if both eyes are affected shed after shed despite corrected humidity, or if the snake's behaviour changes around feeding — missing strikes it would normally land, or refusing food because it effectively cannot see its prey. A vet can remove a stubborn cap safely under proper conditions and, just as usefully, can check whether mites, infection or a husbandry gap is manufacturing the problem repeatedly. Take your shed dates and humidity readings with you; keeping that record in your snake's KinsLe Pet Passport shows the vet the pattern at a glance instead of reconstructing it from memory in the consulting room.