Eye rhyme, also called visual rhyme and sight rhyme, is a similarity in spelling between words that are pronounced differently and hence, not an auditory rhyme

Rhyme

A rhyme is a repetition of similar sounds in two or more words and is most often used in poetry and songs. The word "rhyme" may also refer to a short poem, such as a rhyming couplet or other brief rhyming poem such as nursery rhymes.-Etymology:...

. An example is the pair slaughter and laughter.

Many older English poems

English poetry

The history of English poetry stretches from the middle of the 7th century to the present day. Over this period, English poets have written some of the most enduring poems in Western culture, and the language and its poetry have spread around the globe. Consequently, the term English poetry is...

, particularly those written in Middle English

Middle English

Middle English is the stage in the history of the English language during the High and Late Middle Ages, or roughly during the four centuries between the late 11th and the late 15th century....

 or written in The Renaissance, contain rhymes that were originally true or full rhymes, but as read by modern readers they are now eye rhymes because of shifts in pronunciation

Great Vowel Shift

The Great Vowel Shift was a major change in the pronunciation of the English language that took place in England between 1350 and 1500.The Great Vowel Shift was first studied by Otto Jespersen , a Danish linguist and Anglicist, who coined the term....

. They are called historic rhymes.