If you experience a fuzzy looking and egg shaped red dot in your reflex sight, one of the most common reasons, especially with older shooters, is improper or no vision correction. Many shooters have marginal or even substantial astigmatism and dont get it corrected (eyeglasses. Another challenge for older shooters is the fact that they mostly wear progressive power no line bifocals now instead of the old round and flat top bifocals. Progressive power bifocals, although great for everyday use and keeping one looking younger, present additional problems due to the design of the progressive corridor in the center of the lens. Assuming progressive lenses are prescribed and fitted correctly, the wearer sees fine within a range close to the center of the lens, both in the distant and near (reading) area of the lens but there are gremlins around the peripheral area of the lens. When a shooter aims his crossbow, he is normally looking through the nasal distance portion of his lens where there is typically lots of slop which prevents him from getting a clearly focused picture of the red dot. The results is a fuzzy looking dot with edges not clearly defined. By setting the red dot intensity higher than is needed only makes the effect worse. Admittedly, there are some poor quality reflex sights on the market, with the red dot light being emitted from the top, bottom and sides of the sights body making it impossible to achieve a perfectly round dot but I would say that most of the problems are due to poor or no shooter vision correction.