Table:
Cataract

Magnified view of a cataract seen on examination with a slit lamp
Specialty	Ophthalmology
Symptoms	Faded colors, blurry vision, halos around light, trouble with bright lights, trouble seeing at night[1]
Complications	Falling, depression, blindness[2][3]
Usual onset	Gradual[1]
Causes	Aging, trauma, radiation exposure, following eye surgery[1][4]
Risk factors	Diabetes, smoking tobacco, prolonged exposure to sunlight, alcohol[1]
Diagnostic method	Eye examination[1]
Prevention	Sunglasses, not smoking[1]
Treatment	Glasses, cataract surgery[1]
Frequency	60 million (2015)[5]

Your task is as follows:
In this table image, locate all merged cells and detail their regions using the JSON {'top-left':(X1, Y1), 'bottom-right':(X2, Y2)}. Here, '(X1, Y1)' and '(X2, Y2)' denote the coordinates (row_id, column_id) of the top-left and bottom-right cells of the merged regions, respectively. Keep in mind that row and column IDs start from 1.

The merged cell area is: {'top-left':(1, 1), 'bottom-right':(1, 2)}.