How to select sunglass after Cataract Surgery?

For people who have just had cataract surgery, it's best to wear glasses with lenses that are specifically designed for post-operative use, called "pseudophakic" or "intraocular lens (IOL)" glasses, and they help to correct any residual refractive errors that may still be present after surgery. In addition, as you mentioned, they often have features like anti-reflective coating and UV protection to enhance visual clarity and protect the eyes.

Source: https://www.medicalnewstoday.com/articles/319685

UV protection is blocking harmful wavelength of light into retina.
Transmittance of the surface of a material is its effectiveness in transmitting radiant energy.
What level of Transmittance is recommended?
Sunglasses only block 10-20% radiant energy from light in general

Do you have any suggestions?
Thank you very much for any suggestions (^v^)

Generally, the level of transmittance of sunglasses varies, and is typically measured as a percentage of visible light transmission (VLT). The VLT percentage indicates the amount of visible light that passes through the lenses and reaches the eyes. The VLT range for most sunglasses is 8-18%, with lower percentages indicating darker lenses that transmit less light. The lower the percentage, the better the glasses are at protecting the retina from harmful ultraviolet (UV) and high-energy visible (HEV) light. For those wearing pseudophakic lens, the VLT percentage of the glasses is selected based on the patient's visual needs and the light conditions they will be in. For example, a patient who spends a lot of time outdoors in bright conditions may require lenses with a lower VLT, while a patient who spends most of their time indoors may require lenses with a higher VLT.

For VLT range 8-18%, would Sunglasses only allow 8-18% light pass through and block 82-92% of light source, would it be correct?

Do you have any suggestions?
Thank you very much for any suggestions (^v^)

In the case of 8%, it means that 8% of the light that reaches the material is transmitted through it, while the remaining 92% is absorbed or reflected by the material.

so 8% is darker than 18%.
Thank you very much for suggestions (^v^)

Yes