Hi,
I saw your website looks good,since you are talking about SEO I would suggest you to give alt tags & title tags for images & for the links which helps you a lot in SEO.
Also make sure the page titles are given properly I see the page title in Testimonial, About, shopping cart, etc.. are not proper, please rectify those.
In the catalog page the center content with links are not aligned properly use left align so that it looks good & in a proper manner.
In sitemap the arrows which is used a bullet for the links are not aligned properly to the text with the links. The Friends sub pages are not indented properly, please make sure it is indented. To indented the sub pages separate ul li tags should be used to get indented.
Go to Advanced Search and see the tab "Products found: 0Advanced search" where the UI is totally broken make sure you use fluid width every where in order to use it globally, also the text box are sticked there is no space in between each text boxes.
Background color I see you have used an image but the color is given as white in the CSS, please correct this one also.
please give border="0" for twitter & facebook image in the left bottom of the page, to avoid the blue border as default if incase you require a blue border use the website "995sunglasses.com" blue.
In the right hand side Enter email Text box don't enter any email address in it and click on the arrow icon to submit the email. I see a message "The e-mail address in the E-mail field is invalid.
The E-mail field is mandatory." The E-mail field is mandatory can be removed because you show the email is invalid it means that it has to be entered properly.
Note:-
On the whole I see the website is not quality assured, please make sure the QA is done alone the usability testing since it is a shopping cart website.
If any queries, please contact me.