Going to pick out a contact lens solution can be difficult with all the brands out there. For most people the choice is easy, just buy the cheapest one. Some will choose to take the advice of their Optometrist. However, not all solutions are equal and some are better suited for certain types of contacts. To give solutions their long shelf lives they all contain some sort of preservative. These preservatives can actually make your lenses feel worse to wear. One person may be more sensitive to a preservative than another. Sensitivity to a particular solution doesn't necessarily develop immediately. It can being even after a long time of using a certain brand.
A pair of doctors from Ohio do research on the common brands of contact lens solutions available over the counter and how they interact with popular lens brands. Their findings are used by lots of Optometrists to help them in their practice to make informed decisions about what solution to recommend to their patients. The whole chart is available here. I will summarize the chart and make recommendations as to which solutions are best pair with which lenses.
The most popular material for soft contact lenses today is Silicone Hydrogel. Some of the best known brands like Acuvue Oasys, Purevision and O2Optix are made of silicone hydrogel. The key benefit to this material is its ability to transmit a large amount of oxygen, which allows the front of the eye to breathe. Clear Care is the best choice for any of these brands. The difference between Clear Care and other solutions is that it isn't a saline type of solution. It is a hydrogen peroxide solution that is more abrasive and can clean lenses better than soaking in more traditional solutions. It is better able to get off stubborn deposits. Replenish and Express from Opti-Free are good choices. They show less than 10% staining on most corneas under examination.
Hydrogel is the material that came before silicone hydrogel and was the old popular kid on the block. Soflens 66, Proclear and Acuvue 2 are still popular lenses for some patients. Clear Care and Opti-Free work just as well for these lenses. If you happen to wear Acuvue 2, pretty much any solution will suffice. Including the generic brands available at stores like Walgreens and Target.
A higher quality lens solution is in the best interest of your eyes. They are formulated to be more compatible with newer lens materials like silicone hydrogel. People wear their contacts for longer and longer hours with their hectic lifestyles. Lenses like Night & Day are approved for continuous wear by the FDA. This means that they can be slept in for up to a month when it is time to replace them. Lots of people wear their lenses overnight and for extended periods whether they are designed for that or not. With extended wear of contacts comes a greater chance of infections and corneal ulcers.