**Core Concept**
Spectacles are advised after cataract surgery to correct any refractive errors that may have developed as a result of the surgery. This is crucial for optimal visual rehabilitation and to prevent amblyopia in children. The type and power of the corrective lenses depend on the preoperative refraction and the intraocular lens (IOL) power implanted during surgery.

**Why the Correct Answer is Right**
After cataract surgery, the intraocular lens (IOL) implanted in the eye may not perfectly match the patient's preoperative refraction. This can lead to residual refractive errors, including nearsightedness, farsightedness, or astigmatism. Spectacles are prescribed to correct these refractive errors and improve vision. The power of the corrective lenses is calculated based on the difference between the patient's preoperative refraction and the IOL power.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because spectacles are not just a cosmetic measure, but a necessary tool for correcting refractive errors after cataract surgery.
* **Option B:** This option is incorrect because the decision to prescribe spectacles is based on the patient's postoperative refraction, not their preoperative vision.
* **Option C:** This option is incorrect because the timing of spectacle prescription can vary depending on the individual patient and their specific needs.

**Clinical Pearl / High-Yield Fact**
It's essential to note that some patients may require contact lenses or refractive surgery to correct residual refractive errors after cataract surgery. However, spectacles are usually the first line of treatment.

**Correct Answer: A. Spectacles are advised after cataract surgery to correct refractive errors.**