Difficult and Eye-opening

Difficult adjective - Requiring considerable physical or mental effort.

Eye-opening and difficult are semantically related. In some cases you can use "Eye-opening" instead an adjective "Difficult".

Nearby Word: difficulty

Eye-opening adjective - Causing a strong emotional reaction because of unexpectedness.

Difficult and eye-opening are semantically related. Sometimes you can use "Difficult" instead an adjective phrase "Eye-opening".