Rectangular "Lense"

Hi everybody!
I am really really new to 3d modelling but need it for my 3d-printing projects.
I would like to form a lense on a rectangle - it will be a kind of display. i did not even come close in blende but in sketchup so you get the idea what i want to do… but you know, it should alle be closed! I hope anyone can help me… im kind of lost and really need exactly this form.
thanks in advance!


Ok, I’ve got you covered, mate. Please tell me if I nailed the shape and form?
I’ll upload the file if it meets your criteria.

im making a tutorial for you. it will be up under this link when its done:

also here is the blend file.

the video was too long… aparently i can only do 15 min videos. anyways, feel free to use the file i sendt you.

thank you guys so much! apparently it wasnt exactly what i was looking for.
i found a plugin called “round cube” and it worked out pretty well though.
so thanks again for your time and keep pushing me!
i added it again to my sketchup (getting familiar at least with this application) and here it is: