According to Nielsen (2001), it is 6 times more difficult for someone to use the Internet using a screen reader than using no assistive technology. Nielsen's study was carried out with people who had at least 3 years experience of using the assistive software and at least 3 months experience of using the Internet. 

However, e-learning via the Internet may well enable the student to access more materials and work more independently than they could using traditional methods. 

A student with a visual impairment may also need more time to complete assignments and may need more induction into using a VLE but, it is important to remember that each student will be different. 

Always remember to ask the student directly if you are in any doubt.