A rectangle is the shape that argues least with a face. Straight brows and hard corners sit against softer features without competing, which is why it outsells every other shape here by a distance, and why it is the safe answer when you are buying without trying on.
The width is what to watch. A rectangle that stops short of your temples makes a face look wider than it is; one that runs past them slides. If your current pair fits, read the number printed inside its arm and match the first figure.
Yes, and it is the usual recommendation. Straight lines and defined corners do the opposite of what a round face already does, which adds structure. The wider the frame sits across your cheekbones, the more it works.
What is the difference between rectangle and square sunglasses?
Proportion, not shape. A rectangle is noticeably wider than it is tall; a square is close to equal. Rectangles read as more conservative and suit most faces; squares make a stronger statement and need a longer face to balance them.
Are these polarised?
Every pair carries UV400 lenses, which block 100% of UVA and UVB up to 400 nanometres. That is the protection figure that matters for your eyes. Polarisation is a separate feature about glare, and where a frame has it, the product page says so.
Can I return them if the fit is wrong?
You have 3 days from delivery. If the fault is ours, the refund is full and the reverse pickup is on us. If you simply changed your mind, it is store credit or one exchange per order.