Final answer:
A sutural cataract is a cloudiness along the lens sutures, leading to light dispersion and impaired vision. Parallel laser light is necessary in retinal procedures to focus energy precisely without collateral damage. After cataract surgery, glasses with specific diopters are prescribed to aid vision.
Step-by-step explanation:
A sutural cataract is a type of cataract that refers to the cloudiness occurring along the lines of the sutures of the lens of the eye. Cataracts lead to visual impairment because they cause light to be dispersed or diffused as it passes through the clouded lens. Vitamins A and C are known to help in the protection against the formation of cataracts, and exposure to UV-B may increase the risk. Cataract treatment by replacing the clouded lens with a plastic lens is a common and successful procedure.
When performing laser retinal surgery, it is necessary for the laser light to enter the eye in parallel rays to precisely focus the energy for spot-welding the retina without causing damage to the surrounding areas. If the rays were not parallel, they could converge or diverge before reaching the retina, which might lead to imprecise reparations and potential additional damage.
If the lens is removed due to a cataract, a spectacle lens of about 16 diopters is often prescribed to compensate for the loss of the eye's natural lens and its refractive power to help focus light onto the retina properly.