What are changes that occur in the eye due to monocular congenital cataract ?

Amblyopia: Difficult to anticipate what you are asking. The eye with the cataract will possibly develop amblyopia (incomplete development of the vision) depending on the severity of the cataract. You may see white in the pupil of the eye. Glaucoma could develop.

Poor vision: Dense congenital cataracts Prohibit a clear image to be projected on the retina. The presence of a clear image during the first 8-10 years of life stimulates the retina and optic nerve development after this age the optic nerve (the wiring to the brain) is set for life. Removing a cataract later in life will not improve the vision because the visual data cannot get to the brain. Called amblyopia.

Eye changes Cong.Cat: Congenital Cataract (lens opacity at birth) can cause amblyopia/lazy eye: occurs when eye does not have visual input to the brain for the connection to develop. The eye grows normally otherwise. Early cataract surgery with implant or Contact Lens gives child great chance of vision. More info: eyedoc2020.Blogspot.com