Dear L.,
I worked in the Cosmetics industry for years and years as a make-up artist and skin care consultant, so I hope some of my suggestions will help you.
You will want to look for and eye cream or gel that says "firming," since those products tend to help the skin remain taut and strong. It can help a lot to keep your eye cream in the refrigerator, too. A nice, cool cream can go a long way in helping to reduce puffiness and discomfort. Be sure you do not apply the product directly on the eyelids unless it specifically says that's where you should apply it. All creams and gels can melt and run a little bit, and if you put an eye cream right next to the lash line, there's a possibility it can seep and get into your eyes. Since eye creams are opthamologist tested for safety, that isn't a health problem, but it can cause more puffiness. The Olay products you are using are probably about as effective as anything will be for what you are looking for.
Where dark circles are concerned, creams ans gels can only do so much. The darkness you are seeing is veins and inflammation below the surface of the skin, so cosmetic products can't have a huge effect on it. The skin around the eyes is extremely thin and fragile, so the circles show through easily. Again, cold compresses can help to diminish it, but concealer will be your best friend in disguising it. Use it sparingly over a good cream. Apply it only to the circles, and then blend it with a light tapping motion or by gently rolling your fingertips over it to smooth it out. A concealer pencil can be great for getting a concentrated amount into a small space. Shiseido (department stores) makes a great concealer pencil.
If you send me a private message, I might be able to help you with some more tips, but I will need to know your basic skin tone, etc, to give you the tips that are tailored to helping you the most. I have one little eye massage tip, and some ideas about the tone of the concealer you will want to use.