expression, noun
strong glasses; powerful spectacles
Refers to glasses with a high prescription (strong lenses). The phrase is a noun-like expression often used in everyday conversation.
彼は度の強い眼鏡をかけている。
He wears strong glasses.
度の強い眼鏡だと、目が小さく見えることがある。
With strong glasses, your eyes can sometimes look smaller.
A compound phrase: 度 (ど, 'degree' or 'prescription strength') + の (possessive particle) + 強い (つよい, 'strong') + 眼鏡 (めがね, 'glasses'). The phrase literally means 'glasses of strong degree'.