In most words the sequence <eigh> is pronounced eɪ. Here are examples of this:
eight freight heigh-ho inveigh Leighton neigh neighbour sleigh Speight weigh weight weighty
As you would expect, derivatives of these words like eighty and neighbourhood have the same vowel.
The word height is haɪt and sleight is slaɪt.
The name Leigh is usually li:, but there are some place-names where the pronunciation is laɪ. The sequence <leigh> as an unstressed name ending is pronounced li, as in the name Raleigh and the place-name Chudleigh.