The retinal is a delicate spot that receives images through the eye lens and makes us see the world. If it gets detached, it is very difficult to join it back. Therefore, eye surgeons use:
A) laser beam for welding the retina
B) sound waves for joining
C) micro knives for surgery
D) ultraviolet rays for surgery

Hint: The popular treatment for the eye problem is that the LASIK, which means that Laser Assisted In-Situ Keratomileusis. Laser vision surgery is the popular treatment for the eye defect. It reduces the need of the eyeglass and the contact lenses.

Complete step by step solution:
The laser procedure can help to correct the refractive errors. The eye problem is caused by the imperfect shape of the eyeball or the cornea. The cornea is the part which is the front part of the eye that bends and focuses the light. The eye error is that the light from the object is focused improperly in the retina. The major four errors of the eye are myopia or near-sightedness, hypermetropia or farsightedness, astigmatism and presbyopia.

LASIK makes up about $90\% $ to $95\% $ of all laser vision correction. LASIK is the procedure that permanently changes the shape of the cornea, the clear covering the front of the eye. Sometimes, the micro knife is used to cut the hinged flap in the cornea, after the cut of the cornea, the laser is used to change the shape of the cornea. And also, the laser is used to join the retina or welding the retina.
Thus, the eye surgeons use the laser beam for welding the retina.

Hence, the option (A) is the correct answer.

Note: Other than the LASIK there are several types of surgeries for the treatment of the eye defect, those surgeries also done by using the laser. They are PRK means Photorefractive Keratectomy, LASEK means Laser Epithelial Keratomileusis and LTK means Laser Thermal Keratoplasty.