It is well known in the literature that adult ptosis can be induced or worsen by cataract surgery even with modern sutureless clear cornea phacoemulsification. [1, 2, 3, 4,5,6,7,8] We are presenting this unusual case was the opposite. The ptosis resolved after cataract surgery. A possible effect from the successful management of dry eye disease before cataract surgery is explained. Drooping of the unilateral upper eyelid is unilateral ptosis. Ptosis may be myogenic, neurogenic, and aponeurotic from healthy aging, injury, eye diseases. [9, 10] Ptosis also can be associated with hard contact lens wear, immunological, degenerative, or hereditary disorders, tumors, or infections. [7] Patients with ptosis often present with a lower position of the upper eyelid, complain of a tired appearance, and defect in their superior visual field even blurred vision. The levator muscle controls the position of the eyelid and is innervated by the oculomotor nerve. The Mueller muscle also controls partially by providing sympathetic innervation. The deficiency of these two muscles may cause ptosis. [11] Hering’s law of motor correspondence of a ptosis lid can affect the contralateral lid position [5, 7] as the levator muscles work in synchrony with each other. Therefore, unilateral ptosis can induce a retraction of the contralateral lid or a pseudo retraction. When ptosis is causing visual field defects, the innervation input to both eyelids will increase to reduce the ptosis. There will be a compensatory elevation of eyebrow to reduce the amount of ptosis. [11] These phenomena need to be considered in the evaluation of unilateral ptosis for surgery. Another essential examination, such as Margin Reflex Distance 1 (MRD1), is the crucial measurement for ptosis besides levator function and palpebral fissure. MRD1 is the distance from the margin of the upper lid to the central corneal reflex (normal is between 4.0-4.5 mm). [11]