SFGate

Darzy This is custom and I'm sure pricey, but fits the window just right. : )

Darzy Or, if you don't need light control...you can dress the window like this will demi panels...

Marie Hebson's interiorsBYDESIGN Inc. Hunter Douglas silhouettes or duettes would perfectly fit your windows.
Then you can opt to add soft drapery panels on each end. Good Luck

kathleen MK A friend had a large bamboo and paper fan placed over the usual builders' mini blinds. A thin shelf could hold colored bottle and plants to filter the sun light.
I miss the sun streaming through the arch windows of our first 1980's tract house!

Blind Faith LLC Woven woods could be a good option for you too.

JMittman Designs I made a treatment for a very similar window just recently. We did not have to deal with your sun issue though. I know you said you don't want a blind or shutter in the arch, have you considered uv film to block the sun?

Aja Mazin Redi Shade sells an arch covering for under $20.

It is easily cut it to fit.

Don't like the colour and fabric choices?

Customize it to your taste.!

Julie Thome Draperies, Inc. You do not have enough space above your window for a straight rod. The only thing that will work will be board mounted drapes flush with the ceiling on a slant at each side, meeting in the center at the peak of the ceiling. The drapes would be pulled back with tiebacks or stringing behind, they will not traverse, the headings are fixed. Trying to dig up a pic for you.

Julie Thome Draperies, Inc. Sort of like this but meeting in the center....

Savvy Sewing by the Sea Julie Thome Draperies, Inc., when using the board mounted drapes, are the length on the drapes the same since they are slanted?

Julie Thome Draperies, Inc. Yes, they are fabricated so that they fit the slant at the top but the hems are even at the floor. Obviously a custom job...or judging by your name maybe you can sew and engineer these yourself. There is a large degree of planning for a drape like this..but this is the only style I see working if you do not want to go for shades/or anything else that will cover the semi circle.

Savvy Sewing by the Sea Thanks for the info. I will try & if it doesn't work out, I will have to get them made.

beverlynn Drapes such as JMittman Designs above would work perfectly. It has a much more formal look than blinds. You can open when the sun isn't and issue.

Julie Thome Draperies, Inc. She does not have the room at the top of her windows for a straight rod.

Julie Thome Draperies, Inc. Savvy Sewing..if you're up to it....you need to measure floor to ceiling in the center, and floor to ceiling on the other end of where your board mount will end. I recommend taking the board mounting to about 6" each side of your window. Your drapery will be made with a straight hem at the bottom but a slant cut into the top. If you have ever made pleated drapes before..the pleated area will be cut horizontal, but the space between the pleats will be slanted. You have to make a paper pattern for the top to get this right. Not an easy task, but there are instructions out there for this. I would mount onto a fabric covered 1x2, stapling behind each pleat onto the mount board. You need it secure at the top. You can make tiebacks then for each panel.
Not easy but if you feel you're up to it go for it. You can check your yardage requirement with me she you get round to it. I think you can contact me direct for that on my pro listing.
Good luck.

JMittman Designs I think Julie is right about the straight rod--the window on mine example has more space from top of the peak to top center of the window.

blindsdirectcanada I Agree I think that the Hunter Douglas silhouettes or duettes would perfectly suit your windows.
Then you can add soft drapery panels on each sides of the window for a more finished look.

http://www.blindsdirectcanada.com/blinds-toronto/silhouette-sheer-blinds.html

Aja Mazin Use an adjustable angle rod.

All About Interiors LLC You want to draw your eye upward. By hanging Curtains above the window will do such. You can use two shorter rods on either side that wouldn't interfere with the angles of your ceiling. I hope this helps.

njmomma Some may consider this tacky, but you have an issue with glare on the top half, so my suggestion would be to get some self stick frost for the the top half. Give it that frost look with out the cost. Then you can put some beautiful side panel curtains on some great rods.